Merge branch 'audiomsg_overhaul' (nonshared eventlists and more)

This introduces the following changes:
 - Clone Parts no more share their eventlist. Instead, all changes
   made to one clone are replicated to the other clones' eventlists
 - audio/song->msg{Add,Delete,Change}{Part,Event,Track} have been
   replaced by the corresponding UndoOp operations.
 - Enforcing of const-correctness: No GUI code may ever gain
   writable access to audio/midi/song data structures. Access
   must *always* go through applyOperationGroup. This is now
   enforced.
 - Removed a bunch of DELETETHIS or REMOVE or otherwise commented
   out code
 - Removed dead code
 - Removed unused Audio Messages (that should go through applyOpGroup
   anyway.)

64 files changed, 1787 insertions, 4054 deletions

diff --git a/muse2/muse/arranger/arrangerview.cpp b/muse2/muse/arranger/arrangerview.cpp
index 7974369a..ecedd968 100644
--- a/muse2/muse/arranger/arrangerview.cpp
+++ b/muse2/muse/arranger/arrangerview.cpp
@@ -519,14 +519,14 @@ void ArrangerView::cmd(int cmd)
                   arranger->cmd(Arranger::CMD_INSERT_EMPTYMEAS);
                   break;
             case CMD_DELETE:
-                  if (!MusEGlobal::song->msgRemoveParts()) //automatically does undo if neccessary and returns true then
+                  if (!MusECore::delete_selected_parts())
                   {
                       QMessageBox::StandardButton btn = QMessageBox::warning(
                           this,tr("Remove track(s)"),tr("Are you sure you want to remove this track(s)?"),
                           QMessageBox::Ok|QMessageBox::Cancel, QMessageBox::Ok);
 
                       if (btn == QMessageBox::Cancel)
-                          break;                            //msgRemoveParts() returned false -> no parts to remove?
+                          break;
                       MusEGlobal::song->startUndo();
                       MusEGlobal::audio->msgRemoveTracks(); //TODO FINDME this could still be speeded up!
                       MusEGlobal::song->endUndo(SC_TRACK_REMOVED);
diff --git a/muse2/muse/arranger/pcanvas.cpp b/muse2/muse/arranger/pcanvas.cpp
index 646a9382..2c9c0f29 100644
--- a/muse2/muse/arranger/pcanvas.cpp
+++ b/muse2/muse/arranger/pcanvas.cpp
@@ -64,6 +64,10 @@
 #include "utils.h"
 #include "dialogs.h"
 #include "widgets/pastedialog.h"
+#include "undo.h"
+
+using MusECore::Undo;
+using MusECore::UndoOp;
 
 #define ABS(x) (abs(x))
 
@@ -189,12 +193,12 @@ void PartCanvas::returnPressed()
       if (editMode) {
           //this check is neccessary, because it returnPressed may be called
           //twice. the second call would cause a crash, however!
-          MusECore::Part* oldPart = editPart->part();
-          MusECore::Part* newPart = oldPart->clone();
-          
-          newPart->setName(lineEditor->text());
+          MusECore::Part* part = editPart->part();
           // Indicate do undo, and do port controller values but not clone parts. 
-          MusEGlobal::audio->msgChangePart(oldPart, newPart, true, true, false);
+          
+          Undo operations;
+          operations.push_back(UndoOp(UndoOp::ModifyPartName,part, part->name().toUtf8().data(), lineEditor->text().toUtf8().data())); // FIXME char sucks, better use QString directly.
+          MusEGlobal::song->applyOperationGroup(operations);
           
           editMode = false;
           
@@ -314,7 +318,7 @@ void PartCanvas::moveCanvasItems(CItemList& items, int dp, int dx, DragType dtyp
     
     bool result=moveItem(operations, ci, newpos, dtype);
     if (result)
-    	ci->move(newpos);
+        ci->move(newpos);
     
     if(moving.size() == 1) {
           itemReleased(curItem, newpos);
@@ -333,102 +337,80 @@ void PartCanvas::moveCanvasItems(CItemList& items, int dp, int dx, DragType dtyp
 //---------------------------------------------------------
 
 bool PartCanvas::moveItem(MusECore::Undo& operations, CItem* item, const QPoint& newpos, DragType t)
-      {
-      NPart* npart    = (NPart*) item;
-      MusECore::Part* spart     = npart->part();
-      MusECore::Track* track    = npart->track();
-      MusECore::Track* dtrack=NULL;
-      unsigned dtick  = newpos.x();
-      unsigned ntrack = y2pitch(item->mp().y());
-      MusECore::Track::TrackType type = track->type();
-      if (tracks->index(track) == ntrack && (dtick == spart->tick())) {
-            return false;
-            }
-      if (ntrack >= tracks->size()) {
-            ntrack = tracks->size();
-            if (MusEGlobal::debugMsg)
-                printf("PartCanvas::moveItem - add new track\n");
-            dtrack = MusEGlobal::song->addTrack(operations, type);  // Add at end of list.
-
-            if (type == MusECore::Track::WAVE) {
-                  MusECore::WaveTrack* st = (MusECore::WaveTrack*) track;
-                  MusECore::WaveTrack* dt = (MusECore::WaveTrack*) dtrack;
-                  dt->setChannels(st->channels());
-                  }
-            emit tracklistChanged();
-            }
-      else
-      {      
-            dtrack = tracks->index(ntrack);
-            if (dtrack->type() != type) {
-                  QMessageBox::critical(this, QString("MusE"),
-                     tr("Cannot copy/move/clone to different Track-Type"));
-                  return false;
-                  }
-            }
-      
-      MusECore::Part* dpart;
-      bool clone = (t == MOVE_CLONE || (t == MOVE_COPY && spart->events()->arefCount() > 1));
-      
-      if(t == MOVE_MOVE)
-      {
-        // This doesn't increment aref count, and doesn't chain clones.
-        // It also gives the new part a new serial number, but it is 
-        //  overwritten with the old one by Song::changePart(), from Audio::msgChangePart() below. 
-        dpart = spart->clone();
+{
+    NPart* npart    = (NPart*) item;
+    MusECore::Part* spart     = npart->part();
+    MusECore::Track* track    = npart->track();
+    MusECore::Track* dtrack=NULL;
+    unsigned dtick  = newpos.x(); // FIXME TODO make subtick-compatible!
+    unsigned ntrack = y2pitch(item->mp().y());
+    MusECore::Track::TrackType type = track->type();
+    int new_partend;
+    if (tracks->index(track) == ntrack && (dtick == spart->tick())) {
+        return false;
+    }
+    if (ntrack >= tracks->size()) {
+        ntrack = tracks->size();
+        if (MusEGlobal::debugMsg)
+            printf("PartCanvas::moveItem - add new track\n");
+        dtrack = MusEGlobal::song->addTrack(type);  // Add at end of list. Creates additional Undo entry.
+        
+        if (type == MusECore::Track::WAVE) {
+            MusECore::WaveTrack* st = (MusECore::WaveTrack*) track;
+            MusECore::WaveTrack* dt = (MusECore::WaveTrack*) dtrack;
+            dt->setChannels(st->channels());
+        }
+        emit tracklistChanged();
+    }
+    else
+    {      
+        dtrack = tracks->index(ntrack);
+        if (dtrack->type() != type) {
+            QMessageBox::critical(this, QString("MusE"),
+                                  tr("Cannot copy/move/clone to different Track-Type"));
+                                  return false;
+        }
+    }
+    
+    
+    
+    if(t == MOVE_MOVE)
+    {
+        if (dtrack!=track)
+           operations.push_back(MusECore::UndoOp(MusECore::UndoOp::MovePartToTrack,spart,dtrack,track));
+        
+        operations.push_back(MusECore::UndoOp(MusECore::UndoOp::ModifyPartTick,spart,spart->tick(),dtick));
+        
+        new_partend=(spart->lenTick() + dtick);
+    }  
+    else
+    {
+        MusECore::Part* dpart;
+        bool clone = (t == MOVE_CLONE || (t == MOVE_COPY && spart->hasClones()));
+        
+        // Gives the new part a new serial number.
+        if (clone)
+            dpart = spart->createNewClone();
+        else
+            dpart = spart->duplicate();
+        
+        dpart->setTick(dtick);
         dpart->setTrack(dtrack);
-      }  
-      else
-        // This increments aref count if cloned, and chains clones.
-        // It also gives the new part a new serial number.
-        dpart = dtrack->newPart(spart, clone);
-
-      dpart->setTick(dtick);
-
-      if(t == MOVE_MOVE) 
-        item->setPart(dpart);
-      if (t == MOVE_COPY && !clone) {
-            // Copy Events
-            MusECore::EventList* se = spart->events();
-            MusECore::EventList* de = dpart->events();
-            for (MusECore::iEvent i = se->begin(); i != se->end(); ++i) {
-                  MusECore::Event oldEvent = i->second;
-                  MusECore::Event ev = oldEvent.clone();
-                  de->add(ev);
-                  }
-            }
-
-
-      if (t == MOVE_COPY || t == MOVE_CLONE) {
-            dpart->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it
-                                          // so we must decrement it first :/
-            // These will not increment ref count, and will not chain clones... 
-            // TODO DELETETHIS: is the above comment still correct (by flo93)? i doubt it!
-            operations.push_back(MusECore::UndoOp(MusECore::UndoOp::AddPart,dpart));
-            }
-      else if (t == MOVE_MOVE) {
-            // In all cases found ev lists were same. So this is redundant - Redo incs then decs the same list.
-            // But just in case we ever have two different lists...
-            dpart->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it
-                                          // so we must decrement it first :/
-            spart->events()->incARef(1);  // the later MusEGlobal::song->applyOperationGroup() will decrement it
-                                          // so we must increment it first :/
-            dpart->setSelected(spart->selected());
-            // These will increment ref count if not a clone, and will chain clones...
-            // TODO DELETETHIS: is the above comment still correct (by flo93)? i doubt it!
-            operations.push_back(MusECore::UndoOp(MusECore::UndoOp::ModifyPart,spart, dpart, true, false));
-            
-            spart->setSelected(false);
-            }
-      // else // will never happen -> operations will never be empty
-      
-      if (MusEGlobal::song->len() < (dpart->lenTick() + dpart->tick()))
+        
+        operations.push_back(MusECore::UndoOp(MusECore::UndoOp::AddPart,dpart));
+        
+        new_partend=(dpart->lenTick() + dpart->tick());
+    }
+    
+    if (MusEGlobal::song->len() < new_partend) // FIXME this is buggy anyway.
             operations.push_back(  MusECore::UndoOp(MusECore::UndoOp::ModifySongLen, 
-                                                    dpart->lenTick() + dpart->tick(),
+                                                    new_partend,
                                                     MusEGlobal::song->len() )  );
-      
-      return true;
-      }
+            
+            
+            
+    return true;
+}
 
 //---------------------------------------------------------
 //   raster
@@ -504,15 +486,29 @@ void PartCanvas::partsChanged()
 //---------------------------------------------------------
 
 void PartCanvas::updateSelection()
-      {
+{
+      Undo operations;
+      bool changed=false;
       for (iCItem i = items.begin(); i != items.end(); ++i) {
             NPart* part = (NPart*)(i->second);
-            part->part()->setSelected(i->second->isSelected());
+            operations.push_back(UndoOp(UndoOp::SelectPart, part->part(), i->second->isSelected(), part->part()->selected()));
+            if (i->second->isSelected() != part->part()->selected())
+                changed=true;
       }
-      emit selectionChanged();
-      redraw();
+      
+      if (changed)
+      {
+            MusEGlobal::song->applyOperationGroup(operations);
+            redraw();
       }
 
+      // TODO FIXME: this must be emitted always, because CItem is broken by design:
+      //             CItems hold an Event smart-pointer which allows write access.
+      //             This means, that items can (and will!) be selected bypassing the
+      //             UndoOp::SelectEvent message! FIX THAT! (flo93)
+      emit selectionChanged();
+}
+
 //---------------------------------------------------------
 //   resizeItem
 //---------------------------------------------------------
@@ -680,12 +676,11 @@ bool PartCanvas::deleteItem(CItem* i)
 void PartCanvas::splitItem(CItem* item, const QPoint& pt)
       {
       NPart* np = (NPart*) item;
-      MusECore::Track* t = np->track();
       MusECore::Part*  p = np->part();
       int x = pt.x();
       if (x < 0)
             x = 0;
-      MusEGlobal::song->cmdSplitPart(t, p, AL::sigmap.raster(x, *_raster));
+      split_part(p,AL::sigmap.raster(x, *_raster));
       }
 
 //---------------------------------------------------------
@@ -695,9 +690,7 @@ void PartCanvas::splitItem(CItem* item, const QPoint& pt)
 void PartCanvas::glueItem(CItem* item)
       {
       NPart* np = (NPart*) item;
-      MusECore::Track* t = np->track();
-      MusECore::Part*  p = np->part();
-      MusEGlobal::song->cmdGluePart(t, p);
+      merge_with_next_part(np->part());
       }
 
 //---------------------------------------------------------
@@ -722,7 +715,7 @@ QMenu* PartCanvas::genItemPopup(CItem* item)
       act_copy->setShortcut(Qt::CTRL+Qt::Key_C);
 
       partPopup->addSeparator();
-      int rc = npart->part()->events()->arefCount();
+      int rc = npart->part()->nClones();
       QString st = QString(tr("s&elect "));
       if(rc > 1)
         st += (QString().setNum(rc) + QString(" "));
@@ -856,19 +849,12 @@ void PartCanvas::itemPopup(CItem* item, int n, const QPoint& pt)
             case 15:    // declone
                   {
                   MusECore::Part* spart  = npart->part();
-                  MusECore::Track* track = npart->track();
-                  MusECore::Part* dpart  = track->newPart(spart, false);
-
-                  MusECore::EventList* se = spart->events();
-                  MusECore::EventList* de = dpart->events();
-                  for (MusECore::iEvent i = se->begin(); i != se->end(); ++i) {
-                        MusECore::Event oldEvent = i->second;
-                        MusECore::Event ev = oldEvent.clone();
-                        de->add(ev);
-                        }
-                  // Indicate undo, and do port controller values but not clone parts. 
-                  // changed by flo93: removed start and endUndo, instead changed first bool to true
-                  MusEGlobal::audio->msgChangePart(spart, dpart, true, true, false);
+                  MusECore::Part* dpart  = spart->duplicate(); // dpart will not be member of any clone chain!
+
+                  Undo operations;
+                  operations.push_back(UndoOp(UndoOp::DeletePart, spart));
+                  operations.push_back(UndoOp(UndoOp::AddPart, dpart));
+                  MusEGlobal::song->applyOperationGroup(operations);
                   break;
                   }
             case 16: // Export to file
@@ -892,9 +878,8 @@ void PartCanvas::itemPopup(CItem* item, int n, const QPoint& pt)
             case 17: // File info
                   {
                     MusECore::Part* p = item->part();
-                    MusECore::EventList* el = p->events();
                     QString str = tr("Part name: %1\nFiles:").arg(p->name());
-                    for (MusECore::iEvent e = el->begin(); e != el->end(); ++e) 
+                    for (MusECore::ciEvent e = p->events().begin(); e != p->events().end(); ++e) 
                     {
                       MusECore::Event event = e->second;
                       MusECore::SndFileR f  = event.sndFile();
@@ -913,17 +898,15 @@ void PartCanvas::itemPopup(CItem* item, int n, const QPoint& pt)
                     // Traverse and process the clone chain ring until we arrive at the same part again.
                     // The loop is a safety net.
                     MusECore::Part* p = part; 
-                    int j = part->cevents()->arefCount();
-                    if(j > 0)
+                    
+                    Undo operations;
+                    if(part->hasClones())
                     {
-                      for(int i = 0; i < j; ++i)
-                      {
-                        p->setSelected(true);
-                        p = p->nextClone();
-                        if(p == part)
-                          break;
-                      }
-                      MusEGlobal::song->update(SC_SELECTION);
+                      operations.push_back(UndoOp(UndoOp::SelectPart, p, true, p->selected()));
+                      for(MusECore::Part* it = p->nextClone(); it!=p; it=it->nextClone())
+                        operations.push_back(UndoOp(UndoOp::SelectPart, it, true, it->selected()));
+
+                      MusEGlobal::song->applyOperationGroup(operations);
                     }
                     
                     break;
@@ -1138,7 +1121,7 @@ void PartCanvas::keyPress(QKeyEvent* event)
             if (getCurrentDrag())
                   return;
                 
-            MusEGlobal::song->msgRemoveParts();
+            MusECore::delete_selected_parts();
             return;
             }
       else if (key == shortcuts[SHRT_POS_DEC].key) {
@@ -1492,13 +1475,11 @@ void PartCanvas::keyPress(QKeyEvent* event)
 //    draws a part
 //---------------------------------------------------------
 
-#if 0 // DELETETHIS 430 WHOA!
 void PartCanvas::drawItem(QPainter& p, const CItem* item, const QRect& rect)
       {
       int from   = rect.x();
       int to     = from + rect.width();
 
-      //printf("from %d to %d\n", from,to);
       MusECore::Part* part = ((NPart*)item)->part();
       int pTick  = part->tick();
       from      -= pTick;
@@ -1508,427 +1489,6 @@ void PartCanvas::drawItem(QPainter& p, const CItem* item, const QRect& rect)
       if((unsigned int)to > part->lenTick())
         to = part->lenTick();  
 
-      // Item bounding box x is in tick coordinates, same as rectangle.
-      if(item->bbox().intersect(rect).isNull())
-      {
-        //printf("PartCanvas::drawItem rectangle is null\n");
-        return;
-      }
-      
-      QRect r    = item->bbox();
-      bool clone = part->events()->arefCount() > 1;
-      QBrush brush;
-      
-      //QRect rr = map(r);
-      //QRect rr = p.transform().mapRect(r);
-      //printf("PartCanvas::drawItem called map rx:%d rw:%d  rrx:%d rrw:%d\n", r.x(), r.width(), rr.x(), rr.width());  
-      //printf("PartCanvas::drawItem called map rx:%d rw:%d\n", r.x(), r.width());  
-      //p.save();
-      //p.setWorldMatrixEnabled(false);
-      
-      // NOTE: Optimization: For each item, hasHiddenEvents() is called once in Canvas::draw(), and we use cachedHasHiddenEvents().
-      // Not used for now.
-      //int het = part->cachedHasHiddenEvents();
-      int het = part->hasHiddenEvents();
-        
-      int y_1 = rmapyDev(1);  // Hack, try to replace.
-      double xs_0 =  r.x();
-      double xe_0 =  xs_0 + r.width();
-      double xs_m0 = rmapx_f(xs_0);
-      double xe_m0 = rmapx_f(xe_0);
-      double xs_1 = rmapxDev_f(xs_m0 + 1.0);
-      if(xs_1 > xe_0)
-        xs_1 = xe_0;
-      double xs_2 = rmapxDev_f(xs_m0 + 2.0);
-      if(xs_2 > xe_0)
-        xs_2 = xe_0;
-      double xs_6 = rmapxDev_f(xs_m0 + 6.0);
-      if(xs_6 > xe_0)
-        xs_6 = xe_0;
-      
-      double xe_1 = rmapxDev_f(xe_m0 - 1.0);
-      if(xe_1 < xs_0)
-        xe_1 = xs_0;
-      double xe_2 = rmapxDev_f(xe_m0 - 2.0);
-      if(xe_2 < xs_0)
-        xe_2 = xs_0;
-      double xe_6 = rmapxDev_f(xe_m0 - 6.0);
-      if(xe_6 < xs_0)
-        xe_6 = xs_0;
-      
-      double ys_0 =  r.y();
-      double ye_0 =  ys_0 + r.height();
-      double ys_m0 = rmapy_f(ys_0);
-      double ye_m0 = rmapy_f(ye_0);
-      double ys_1 = rmapyDev_f(ys_m0 + 1.0);
-      if(ys_1 > ye_0)
-        ys_1 = ye_0;
-      double ys_2 = rmapyDev_f(ys_m0 + 2.0);
-      if(ys_2 > ye_0)
-        ys_2 = ye_0;
-      
-      double ye_1 = rmapyDev_f(ye_m0 - 1.0);
-      if(ye_1 < ys_0)
-        ye_1 = ys_0;
-      double ye_2 = rmapyDev_f(ye_m0 - 2.0);
-      if(ye_2 < ys_0)
-        ye_2 = ys_0;
-      
-      int cidx = part->colorIndex();
-      if (item->isMoving()) 
-      {
-            QColor c(Qt::gray);
-            c.setAlpha(MusEGlobal::config.globalAlphaBlend);
-            QLinearGradient gradient(r.topLeft(), r.bottomLeft());
-            gradient.setColorAt(0, c);
-            gradient.setColorAt(1, c.darker());
-            brush = QBrush(gradient);
-      }
-      else 
-      if (part->selected()) 
-      {
-          QColor c(Qt::black);
-          c.setAlpha(MusEGlobal::config.globalAlphaBlend);
-          QLinearGradient gradient(r.topLeft(), r.bottomLeft());
-          // Use a colour only about 20% lighter than black, rather than the 50% we use in MusECore::gGradientFromQColor
-          //  and is used in darker()/lighter(), so that it is distinguished a bit better from grey non-part tracks.
-          //c.setRgba(64, 64, 64, c.alpha());        
-          gradient.setColorAt(0, QColor(51, 51, 51, MusEGlobal::config.globalAlphaBlend));
-          gradient.setColorAt(1, c);
-          brush = QBrush(gradient);
-      }
-      else
-      if (part->mute()) 
-      {
-            QColor c(Qt::white);
-            c.setAlpha(MusEGlobal::config.globalAlphaBlend);
-            QLinearGradient gradient(r.topLeft(), r.bottomLeft());
-            gradient.setColorAt(0, c);
-            gradient.setColorAt(1, c.darker());
-            brush = QBrush(gradient);
-            
-            // Not good. Aliasing missing lines happening at different mags. 
-            // And it's too much. If notes + automation is displayed (by removing 'return' below), cross hatch interferes.
-            // TODO: Maybe try to draw a nice gradient SINGLE cross (or STAR) from corner to corner instead. 
-            // Then remove the 'return' below and let it draw the name and notes. 
-            //brush.setStyle(Qt::DiagCrossPattern);
-            //p.fillRect(rf, brush);
-      }
-      else
-      {
-            QColor c(MusEGlobal::config.partColors[cidx]);
-            c.setAlpha(MusEGlobal::config.globalAlphaBlend);
-            brush = QBrush(MusECore::gGradientFromQColor(c, r.topLeft(), r.bottomLeft()));
-      }  
-      
-      double h = r.height();
-      double s = h / 4.0;
-      double y0 = r.y();
-      double y1 = y0 + s;
-      double y2 = y0 + s * 2.0;
-      double y3 = y0 + s * 3.0;
-      double y4 = y0 + h;
-      
-      QPointF points[16];   
-      int pts;
-      
-      //
-      // Fill the part rectangles, accounting for hidden events by using 'jagged' edges...
-      //
-      
-      p.setBrush(brush);
-      p.setPen(Qt::NoPen);
-      if(het)
-      {
-        pts = 0;
-        if(het == (MusECore::Part::LeftEventsHidden | MusECore::Part::RightEventsHidden))
-        {
-          points[pts++] = QPointF(xs_0, y0);
-          points[pts++] = QPointF(xe_0, y0);
-          points[pts++] = QPointF(xe_6, y1);
-          points[pts++] = QPointF(xe_0, y2);
-          points[pts++] = QPointF(xe_6, y3);
-          points[pts++] = QPointF(xe_0, y4);
-          points[pts++] = QPointF(xs_0, y4);
-          points[pts++] = QPointF(xs_6, y3);
-          points[pts++] = QPointF(xs_0, y2);
-          points[pts++] = QPointF(xs_6, y1);
-          p.drawConvexPolygon(points, pts);   // Help says may be faster on some platforms (X11).
-        }
-        else
-        if(het == MusECore::Part::LeftEventsHidden)
-        {
-          points[pts++] = QPointF(xs_0, y0);
-          points[pts++] = QPointF(xe_0, y0);
-          points[pts++] = QPointF(xe_0, y4);
-          points[pts++] = QPointF(xs_0, y4);
-          points[pts++] = QPointF(xs_6, y3);
-          points[pts++] = QPointF(xs_0, y2);
-          points[pts++] = QPointF(xs_6, y1);
-          p.drawConvexPolygon(points, pts);   
-        }
-        else
-        if(het == MusECore::Part::RightEventsHidden)
-        {
-          points[pts++] = QPointF(xs_0, y0);
-          points[pts++] = QPointF(xe_0, y0);
-          
-          points[pts++] = QPointF(xe_6, y1);
-          points[pts++] = QPointF(xe_0, y2);
-          points[pts++] = QPointF(xe_6, y3);
-          points[pts++] = QPointF(xe_0, y4);
-          points[pts++] = QPointF(xs_0, y4);
-          p.drawConvexPolygon(points, pts);   
-        }
-        
-        //
-        // Draw remaining 'hidden events' decorations with 'jagged' edges...
-        //
-                      
-        int part_r, part_g, part_b, brightness, color_brightness;
-        MusEGlobal::config.partColors[cidx].getRgb(&part_r, &part_g, &part_b);
-        brightness =  part_r*29 + part_g*59 + part_b*12;
-        //if ((brightness < 12000 || part->selected()) && !part->mute() && !item->isMoving())
-        //  color_brightness=223;   // too dark: use lighter color 
-        //else
-        //  color_brightness=32;  // otherwise use dark color 
-        if ((brightness >= 12000 && !part->selected()))
-          color_brightness=32;    // too light: use dark color 
-        else
-          color_brightness=223;   // too dark: use lighter color 
-        QColor c(color_brightness,color_brightness,color_brightness, MusEGlobal::config.globalAlphaBlend);
-        p.setBrush(QBrush(MusECore::gGradientFromQColor(c, r.topLeft(), r.bottomLeft())));
-        //p.setBrush(QBrush(c));
-        if(het & MusECore::Part::RightEventsHidden)
-        {
-          pts = 0;
-          points[pts++] = QPointF(xe_0, y0);
-          points[pts++] = QPointF(xe_0, y4);
-          points[pts++] = QPointF(xe_6, y3);
-          points[pts++] = QPointF(xe_0, y2);
-          points[pts++] = QPointF(xe_6, y1);
-          p.drawConvexPolygon(points, pts);   
-        }
-        if(het & MusECore::Part::LeftEventsHidden)
-        {
-          pts = 0;
-          points[pts++] = QPointF(xs_0, y0);
-          points[pts++] = QPointF(xs_6, y1);
-          points[pts++] = QPointF(xs_0, y2);
-          points[pts++] = QPointF(xs_6, y3);
-          points[pts++] = QPointF(xs_0, y4);
-          p.drawConvexPolygon(points, pts);   
-        }
-      }  
-      else
-      {
-        p.fillRect(r, brush);
-      }
-          
-      MusECore::MidiPart* mp = 0;
-      MusECore::WavePart* wp = 0;
-      MusECore::Track::TrackType type = part->track()->type();
-      if (type == MusECore::Track::WAVE) {
-            wp =(MusECore::WavePart*)part;
-            }
-      else {
-            mp = (MusECore::MidiPart*)part;
-            }
-
-      if (wp)
-          drawWavePart(p, rect, wp, r);
-      else if (mp)
-      {
-          drawMidiPart(p, rect, mp->events(), (MusECore::MidiTrack*)part->track(), mp, r, mp->tick(), from, to);  
-      }
-
-  #if 0
-        //
-        // Now draw the borders...
-        // Works great but requires clones be drawn with the highest priority on top of all other parts, in Canvas::draw.
-        //
-        
-        QPen pen(part->selected() ? MusEGlobal::config.partColors[i] : Qt::black, 2.0, clone ? Qt::DotLine : Qt::SolidLine);
-        pen.setCosmetic(true);
-        p.setPen(pen); 
-        p.setBrush(Qt::NoBrush);
-        p.drawRect(r);
-        
-  #else 
-        //
-        // Now draw the borders, using custom segments...
-        //
-        
-        // FIXME NOTE: For 1-pixel wide lines, setting pen style to anything other than solid didn't work out well. 
-        // Much too screwy - the single-width lines kept getting shifted one pixel over intermittently. 
-        // I tried EVERYTHING to make sure x is proper but the painter keeps shifting them over.
-        // Meanwhile the fills are correct. Seems painter doesn't like line patterns, whether stock or custom.
-        // Therefore I was forced to manually draw the left and right segments. 
-        // It works. Which seems to be more proof that painter is handling line patterns and pen widths badly... 
-        // DO NOT ERASE COMMENTED CODE BELOW for now, in case it can be fixed. Tim. p4.0.29
-        
-        p.setBrush(Qt::NoBrush);
-        
-        QColor pc((part->mute() || item->isMoving())? Qt::white : MusEGlobal::config.partColors[cidx]);
-        QPen penSelect1H(pc);
-        QPen penSelect2H(pc, 2.0);
-        QPen penSelect1V(pc);
-        QPen penSelect2V(pc, 2.0);
-        penSelect1H.setCosmetic(true);
-        penSelect2H.setCosmetic(true);
-        penSelect1V.setCosmetic(true);
-        penSelect2V.setCosmetic(true);
-        
-        pc = Qt::black;
-        QPen penNormal1H(pc);
-        QPen penNormal2H(pc, 2.0);
-        QPen penNormal1V(pc);
-        QPen penNormal2V(pc, 2.0);
-        penNormal1H.setCosmetic(true);
-        penNormal2H.setCosmetic(true);
-        penNormal1V.setCosmetic(true);
-        penNormal2V.setCosmetic(true);
-        
-        QVector<qreal> customDashPattern;
-        if(clone)
-        {
-          customDashPattern << 4.0 << 8.0;
-          penSelect1H.setDashPattern(customDashPattern);
-          penNormal1H.setDashPattern(customDashPattern);
-          //penSelect1V.setDashPattern(customDashPattern);
-          //penNormal1V.setDashPattern(customDashPattern);
-          customDashPattern.clear();
-          customDashPattern << 2.0 << 4.0;
-          penSelect2H.setDashPattern(customDashPattern);
-          penNormal2H.setDashPattern(customDashPattern);
-          //penSelect2V.setDashPattern(customDashPattern);
-          //penNormal2V.setDashPattern(customDashPattern);
-        }  
-        
-        pc = Qt::white;
-        QPen penHidden1(pc);
-        QPen penHidden2(pc, 2.0);
-        penHidden2.setCosmetic(true);
-        //customDashPattern.clear();
-        //customDashPattern << 2.0 << 10.0;
-        //penHidden1.setDashPattern(customDashPattern);
-        //customDashPattern.clear();
-        //customDashPattern << 1.0 << 5.0;
-        //penHidden2.setDashPattern(customDashPattern);
-        
-        bool lbt = ((NPart*)item)->leftBorderTouches;
-        bool rbt = ((NPart*)item)->rightBorderTouches;
-        
-        QLineF l1( lbt?xs_1:xs_0, ys_0,   rbt?xe_1:xe_0, ys_0);                     // Top 
-        //QLineF l2(rbt?xe_1:xe_0,  r.y() + (rbt?y_1:y_2) - 1,       rbt?xe_1:xe_0, r.y() + r.height() - 1);        // Right 
-        QLineF l3( lbt?xs_1:xs_0, ye_0,   rbt?xe_1:xe_0, ye_0);  // Bottom
-        //QLineF l4(r.x(), r.y() + (lbt?y_1:y_2),            r.x(), r.y() + r.height() - (lbt?y_1:y_2));       // Left
-        
-        if(het & MusECore::Part::RightEventsHidden)
-          p.setPen(((NPart*)item)->rightBorderTouches ? penHidden1 : penHidden2); 
-        else  
-        {
-          if(((NPart*)item)->rightBorderTouches)              
-            p.setPen(part->selected() ? penSelect1V : penNormal1V); 
-          else  
-            p.setPen(part->selected() ? penSelect2V : penNormal2V); 
-        }  
-        //p.drawLine(l2);        // Right line
-        
-        double xx = rbt?xe_1:xe_0; 
-        if(clone)
-        {
-          double yinc = 7.0 * y_1;
-          for(double yy = (rbt?ys_1:ys_2); yy < ye_2; yy += yinc)
-          {
-            double yi = (rbt?3.0:2.0) * y_1;
-            if(yy + yi > ye_2)
-              yi = ye_2 - yy;
-            p.drawLine(QPointF(xx, yy), QPointF(xx, yy + yi));      // Right dashed line
-          }   
-        }
-        else  
-          p.drawLine(QPointF(xx, rbt?ys_1:ys_2), QPointF(xx, rbt?ye_1:ye_2));      // Right line
-        
-        if(het & MusECore::Part::LeftEventsHidden)
-          p.setPen(((NPart*)item)->leftBorderTouches ? penHidden1 : penHidden2); 
-        else  
-        {
-          if(((NPart*)item)->leftBorderTouches)              
-            p.setPen(part->selected() ? penSelect1V : penNormal1V); 
-          else  
-            p.setPen(part->selected() ? penSelect2V : penNormal2V); 
-        }  
-        //p.drawLine(l4);        //  Left line
-        
-        xx = xs_0;
-        if(clone)
-        {
-          double yinc = 7.0 * y_1;
-          for(double yy = (lbt?ys_1:ys_2); yy < ye_2; yy += yinc)
-          {
-            double yi = (lbt?3.0:2.0) * y_1;
-            if(yy + yi > ye_2)
-              yi = ye_2 - yy;
-            p.drawLine(QPointF(xx, yy), QPointF(xx, yy + yi));      // Left dashed line
-          }   
-        }
-        else  
-          p.drawLine(QPointF(xx, lbt?ys_1:ys_2), QPointF(xx, lbt?ye_1:ye_2));      // Left line
-        
-        p.setPen(part->selected() ? penSelect2H : penNormal2H); 
-        p.drawLine(l1);  // Top line
-        p.drawLine(l3);  // Bottom line
-        
-  #endif
- 
-      //p.restore();
-      
-      if (MusEGlobal::config.canvasShowPartType & 1) {     // show names
-            // draw name
-            // FN: Set text color depending on part color (black / white)
-            int part_r, part_g, part_b, brightness;
-            // Since we'll draw the text on the bottom (to accommodate drum 'slivers'),
-            //  get the lowest colour in the gradient used to draw the part.
-            QRect rr = map(r);
-            rr.setX(rr.x() + 3);
-            MusECore::gGradientFromQColor(MusEGlobal::config.partColors[cidx], rr.topLeft(), rr.bottomLeft()).stops().last().second.getRgb(&part_r, &part_g, &part_b);
-            brightness =  part_r*29 + part_g*59 + part_b*12;
-            //bool rev = (brightness < 12000 || part->selected()) && !part->mute() && !item->isMoving();
-            bool rev = brightness >= 12000 && !part->selected();
-            p.save();
-            p.setFont(MusEGlobal::config.fonts[4]);
-            p.setWorldMatrixEnabled(false);
-            if (rev)
-              p.setPen(Qt::white); 
-            else
-              p.setPen(Qt::black);   
-            p.drawText(rr.translated(1, 1), Qt::AlignBottom|Qt::AlignLeft, part->name());
-            if (rev)
-              p.setPen(Qt::black);  
-            else
-              p.setPen(Qt::white);   
-            p.drawText(rr, Qt::AlignBottom|Qt::AlignLeft, part->name());
-            p.restore();
-            }
-      }
-#endif
-
-void PartCanvas::drawItem(QPainter& p, const CItem* item, const QRect& rect)
-      {
-      int from   = rect.x();
-      int to     = from + rect.width();
-
-      MusECore::Part* part = ((NPart*)item)->part();
-      int pTick  = part->tick();
-      from      -= pTick;
-      to        -= pTick;
-      if(from < 0)
-        from = 0;
-      if((unsigned int)to > part->lenTick())
-        to = part->lenTick();  
-
-      bool clone = part->events()->arefCount() > 1;
       QBrush brush;
       
       QRect r    = item->bbox();
@@ -2142,23 +1702,18 @@ void PartCanvas::drawItem(QPainter& p, const CItem* item, const QRect& rect)
       MusECore::MidiPart* mp = 0;
       MusECore::WavePart* wp = 0;
       MusECore::Track::TrackType type = part->track()->type();
-      if (type == MusECore::Track::WAVE) {
+      if (type == MusECore::Track::WAVE)
             wp =(MusECore::WavePart*)part;
-            }
-      else {
+      else
             mp = (MusECore::MidiPart*)part;
-            }
 
       if (wp)
           drawWavePart(p, rect, wp, r);
       else if (mp)
-      {
-          drawMidiPart(p, rect, mp->events(), (MusECore::MidiTrack*)part->track(), mp, r, mp->tick(), from, to);  
-      }
+          drawMidiPart(p, rect, mp, r, from, to);
 
       p.setWorldMatrixEnabled(false);
         
-  #if 1 // DELETETHIS remove wrapping #if
         //
         // Now draw the borders, using custom segments...
         //
@@ -2186,7 +1741,7 @@ void PartCanvas::drawItem(QPainter& p, const CItem* item, const QRect& rect)
         penNormal2V.setCosmetic(true);
                 
         QVector<qreal> customDashPattern;
-        if(clone)
+        if(part->hasClones())
         {
           customDashPattern << 4.0 << 6.0;
           penSelect1H.setDashPattern(customDashPattern);
@@ -2249,8 +1804,6 @@ void PartCanvas::drawItem(QPainter& p, const CItem* item, const QRect& rect)
         QLine l3(lbx_c, ye_0, rbx_c, ye_0);
         p.drawLine(l3);  // Bottom line
         
-  #endif
-      
       if (MusEGlobal::config.canvasShowPartType & 1) {     // show names
             // draw name
             // FN: Set text color depending on part color (black / white)
@@ -2314,7 +1867,12 @@ void PartCanvas::drawMoving(QPainter& p, const CItem* item, const QRect&)
 //    pr - part rectangle
 //---------------------------------------------------------
 
-void PartCanvas::drawMidiPart(QPainter& p, const QRect&, MusECore::EventList* events, MusECore::MidiTrack *mt, MusECore::MidiPart *pt, const QRect& r, int pTick, int from, int to)
+void PartCanvas::drawMidiPart(QPainter& p, const QRect& rect, MusECore::MidiPart* midipart, const QRect& r, int from, int to)
+{
+	drawMidiPart(p, rect, midipart->events(), midipart->track(), midipart, r, midipart->tick(), from, to);
+}
+
+void PartCanvas::drawMidiPart(QPainter& p, const QRect&, const MusECore::EventList& events, MusECore::MidiTrack *mt, MusECore::MidiPart *pt, const QRect& r, int pTick, int from, int to)
 {
   int color_brightness;
   QColor eventColor;
@@ -2343,9 +1901,9 @@ void PartCanvas::drawMidiPart(QPainter& p, const QRect&, MusECore::EventList* ev
             // Do not allow this, causes segfault.
             if(from <= to)
             {
-              MusECore::iEvent ito(events->lower_bound(to));
+              MusECore::ciEvent ito(events.lower_bound(to));
 
-              for (MusECore::iEvent i = events->lower_bound(from); i != ito; ++i) {
+              for (MusECore::ciEvent i = events.lower_bound(from); i != ito; ++i) {
                     MusECore::EventType type = i->second.type();
                     int a = i->second.dataA() | 0xff;
                     if (
@@ -2371,12 +1929,12 @@ void PartCanvas::drawMidiPart(QPainter& p, const QRect&, MusECore::EventList* ev
       using std::map;
       using std::pair;
       
-      MusECore::iEvent ito(events->lower_bound(to));
+      MusECore::ciEvent ito(events.lower_bound(to));
       bool isdrum = (mt->type() == MusECore::Track::DRUM  ||  mt->type() == MusECore::Track::NEW_DRUM);
 
       // draw controllers ------------------------------------------
       p.setPen(QColor(192,192,color_brightness/2));
-      for (MusECore::iEvent i = events->begin(); i != ito; ++i) { // PITCH BEND
+      for (MusECore::ciEvent i = events.begin(); i != ito; ++i) { // PITCH BEND
             int t  = i->first + pTick;
 
             MusECore::EventType type = i->second.type();
@@ -2393,7 +1951,7 @@ void PartCanvas::drawMidiPart(QPainter& p, const QRect&, MusECore::EventList* ev
       }
 
       p.setPen(QColor(192,color_brightness/2,color_brightness/2));
-      for (MusECore::iEvent i = events->begin(); i != ito; ++i) { // PAN
+      for (MusECore::ciEvent i = events.begin(); i != ito; ++i) { // PAN
             int t  = i->first + pTick;
 
             MusECore::EventType type = i->second.type();
@@ -2410,7 +1968,7 @@ void PartCanvas::drawMidiPart(QPainter& p, const QRect&, MusECore::EventList* ev
       }
 
       p.setPen(QColor(color_brightness/2,192,color_brightness/2));
-      for (MusECore::iEvent i = events->begin(); i != ito; ++i) { // VOLUME
+      for (MusECore::ciEvent i = events.begin(); i != ito; ++i) { // VOLUME
             int t  = i->first + pTick;
 
             MusECore::EventType type = i->second.type();
@@ -2427,7 +1985,7 @@ void PartCanvas::drawMidiPart(QPainter& p, const QRect&, MusECore::EventList* ev
       }
 
       p.setPen(QColor(0,0,255));
-      for (MusECore::iEvent i = events->begin(); i != ito; ++i) { // PROGRAM CHANGE
+      for (MusECore::ciEvent i = events.begin(); i != ito; ++i) { // PROGRAM CHANGE
             int t  = i->first + pTick;
 
             MusECore::EventType type = i->second.type();
@@ -2454,7 +2012,7 @@ void PartCanvas::drawMidiPart(QPainter& p, const QRect&, MusECore::EventList* ev
       
       if (MusEGlobal::config.canvasShowPartType & 4) //y-stretch?
       {
-        for (MusECore::iEvent i = events->begin(); i != events->end(); ++i)
+        for (MusECore::ciEvent i = events.begin(); i != events.end(); ++i)
         {
           if (i->second.type()==MusECore::Note)
           {
@@ -2493,13 +2051,13 @@ void PartCanvas::drawMidiPart(QPainter& p, const QRect&, MusECore::EventList* ev
         if (MusEGlobal::heavyDebugMsg)
         {
             if (!isdrum)
-                printf("DEBUG: arranger: cakewalk enabled, y-stretching from %i to %i. eventlist=%p\n",lowest_pitch, highest_pitch, events);
+                printf("DEBUG: arranger: cakewalk enabled, y-stretching from %i to %i.\n",lowest_pitch, highest_pitch);
             else
             {
                 printf("DEBUG: arranger: cakewalk enabled, y-stretching drums: ");;
                 for (map<int,int>::iterator it=y_mapper.begin(); it!=y_mapper.end(); it++)
                     printf("%i ", it->first);
-                printf("; eventlist=%p\n",events); 
+                printf("\n"); 
             }
         }
       }
@@ -2516,7 +2074,7 @@ void PartCanvas::drawMidiPart(QPainter& p, const QRect&, MusECore::EventList* ev
       }
 
       p.setPen(eventColor);
-      for (MusECore::iEvent i = events->begin(); i != ito; ++i) {
+      for (MusECore::ciEvent i = events.begin(); i != ito; ++i) {
             int t  = i->first + pTick;
             int te = t + i->second.lenTick();
 
@@ -2570,8 +2128,7 @@ void PartCanvas::drawWavePart(QPainter& p,
       int h  = hh/2;
       int y  = pr.y() + h;
 
-      MusECore::EventList* el = wp->events();
-      for (MusECore::iEvent e = el->begin(); e != el->end(); ++e) {
+      for (MusECore::ciEvent e = wp->events().begin(); e != wp->events().end(); ++e) {
             int cc = hh % 2 ? 0 : 1;
             MusECore::Event event = e->second;
             MusECore::SndFileR f  = event.sndFile();
@@ -2779,9 +2336,7 @@ void PartCanvas::copy_in_range(MusECore::PartList* pl_)
           MusECore::Part* p1;
           MusECore::Part* p2;
           
-          track->splitPart(part, lpos, p1, p2);
-          p1->events()->incARef(-1);
-          p2->events()->incARef(-1);
+          part->splitPart(lpos, p1, p2);
           
           part=p2;
         }
@@ -2791,9 +2346,7 @@ void PartCanvas::copy_in_range(MusECore::PartList* pl_)
           MusECore::Part* p1;
           MusECore::Part* p2;
           
-          track->splitPart(part, rpos, p1, p2);
-          p1->events()->incARef(-1);
-          p2->events()->incARef(-1);
+          part->splitPart(rpos, p1, p2);
 
           part=p1;
         }
@@ -2889,7 +2442,7 @@ MusECore::Undo PartCanvas::pasteAt(const QString& pt, MusECore::Track* track, un
                         if (tag == "part") {                              
                               // Read the part.
                               MusECore::Part* p = 0;
-                              p = readXmlPart(xml, track, clone, toTrack);
+                              p = MusECore::Part::readFromXml(xml, track, clone, toTrack);
 
                               // If it could not be created...
                               if(!p)
@@ -2899,9 +2452,6 @@ MusECore::Undo PartCanvas::pasteAt(const QString& pt, MusECore::Track* track, un
                                 break;
                               } 
 
-                              p->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it
-                                                        // so we must decrement it first :/
-                              
                               // Increment the number of parts done.
                               ++done;
                               
@@ -3210,13 +2760,9 @@ void PartCanvas::viewDropEvent(QDropEvent* event)
 
                 if (!track) { // we need to create a track for this drop
                     if (text.endsWith(".mpt", Qt::CaseInsensitive)) {
-                        MusECore::Undo operations;
-                        track = MusEGlobal::song->addTrack(operations, MusECore::Track::MIDI);    // Add at end of list.
-                        MusEGlobal::song->applyOperationGroup(operations);
+                        track = MusEGlobal::song->addTrack(MusECore::Track::MIDI);    // Add at end of list.
                     } else {
-                        MusECore::Undo operations;
-                        track = MusEGlobal::song->addTrack(operations, MusECore::Track::WAVE);    // Add at end of list.
-                        MusEGlobal::song->applyOperationGroup(operations);
+                        track = MusEGlobal::song->addTrack(MusECore::Track::WAVE);    // Add at end of list.
                     }
                 }
                 if (track->type() == MusECore::Track::WAVE &&
@@ -3475,10 +3021,9 @@ void PartCanvas::drawTopItem(QPainter& p, const QRect& rect)
                MusECore::MidiTrack *mt = (MusECore::MidiTrack*)track;
                QRect partRect(startPos,yPos, MusEGlobal::song->cpos()-startPos, track->height()); // probably the wrong rect
                MusECore::EventList myEventList;
-	       MusECore::MPEventList *el = mt->mpevents();
-               if (el->size()) {
+               if (mt->mpevents.size()) {
 
-                 for (MusECore::ciMPEvent i = el->begin(); i != el->end(); ++i) {
+                 for (MusECore::ciMPEvent i = mt->mpevents.begin(); i != mt->mpevents.end(); ++i) {
                     MusECore::MidiPlayEvent pe = *i;
 
                     if (pe.isNote() && !pe.isNoteOff()) {
@@ -3501,7 +3046,7 @@ void PartCanvas::drawTopItem(QPainter& p, const QRect& rect)
                     }
                  }
                }
-               drawMidiPart(p, rect, &myEventList, mt, 0, partRect,startPos,0,MusEGlobal::song->cpos()-startPos);
+               drawMidiPart(p, rect, myEventList, mt, 0, partRect,startPos,0,MusEGlobal::song->cpos()-startPos);
            }
            yPos+=track->height();
       }
diff --git a/muse2/muse/arranger/pcanvas.h b/muse2/muse/arranger/pcanvas.h
index d34a26b6..f1d2b1a1 100644
--- a/muse2/muse/arranger/pcanvas.h
+++ b/muse2/muse/arranger/pcanvas.h
@@ -143,7 +143,8 @@ class PartCanvas : public Canvas {
       void paste(bool clone = false, paste_mode_t paste_mode = PASTEMODE_MIX, bool to_single_track=false, int amount=1, int raster=1536);
       MusECore::Undo pasteAt(const QString&, MusECore::Track*, unsigned int, bool clone = false, bool toTrack = true, int* finalPosPtr = NULL, std::set<MusECore::Track*>* affected_tracks = NULL);
       void drawWavePart(QPainter&, const QRect&, MusECore::WavePart*, const QRect&);
-      void drawMidiPart(QPainter&, const QRect& rect, MusECore::EventList* events, MusECore::MidiTrack*mt, MusECore::MidiPart*pt, const QRect& r, int pTick, int from, int to);
+      void drawMidiPart(QPainter&, const QRect& rect, const MusECore::EventList& events, MusECore::MidiTrack* mt, MusECore::MidiPart* pt, const QRect& r, int pTick, int from, int to);
+	  void drawMidiPart(QPainter&, const QRect& rect, MusECore::MidiPart* midipart, const QRect& r, int from, int to);
       MusECore::Track* y2Track(int) const;
       void drawAudioTrack(QPainter& p, const QRect& r, const QRect& bbox, MusECore::AudioTrack* track);
       void drawAutomation(QPainter& p, const QRect& r, MusECore::AudioTrack* track);
diff --git a/muse2/muse/arranger/tlist.cpp b/muse2/muse/arranger/tlist.cpp
index 5cea444d..7ebcad4d 100644
--- a/muse2/muse/arranger/tlist.cpp
+++ b/muse2/muse/arranger/tlist.cpp
@@ -75,6 +75,8 @@
 #include "dssihost.h"
 #endif
 
+using MusECore::UndoOp;
+
 namespace MusEGui {
 
 static const int MIN_TRACKHEIGHT = 20;
@@ -599,13 +601,10 @@ void TList::returnPressed()
                             }
                       }
                       
-                MusEGlobal::song->startUndo();
-                MusEGlobal::song->addUndo(MusECore::UndoOp(MusECore::UndoOp::ModifyTrackName, 
+                MusEGlobal::song->applyOperation(MusECore::UndoOp(MusECore::UndoOp::ModifyTrackName, 
                                                           editTrack, 
                                                           editTrack->name().toLatin1().constData(), 
                                                           editor->text().toLatin1().constData()));
-                editTrack->setName(editor->text());
-                MusEGlobal::song->endUndo(-1);                   //uagh, why "-1", why no proper flags?
                 }
         }    
         
@@ -640,16 +639,10 @@ void TList::chanValueFinished()
           channel = 0;
         if(channel != mt->outChannel()) 
         {
-              MusEGlobal::song->startUndo();
-              MusEGlobal::song->addUndo(MusECore::UndoOp(MusECore::UndoOp::ModifyTrackChannel, 
+              MusEGlobal::song->applyOperation(MusECore::UndoOp(MusECore::UndoOp::ModifyTrackChannel, 
                                                           editTrack, 
                                                           mt->outChannel(), 
                                                           channel));
-              MusEGlobal::audio->msgIdle(true);
-              mt->setOutChanAndUpdate(channel);
-              MusEGlobal::audio->msgIdle(false);
-              MusEGlobal::audio->msgUpdateSoloStates();                   
-              MusEGlobal::song->endUndo(SC_MIDI_TRACK_PROP);
         }      
       }
     }
@@ -667,13 +660,10 @@ void TList::chanValueFinished()
                   n = 1;
             if(n != at->channels()) 
             {
-                  MusEGlobal::song->startUndo();
-                  MusEGlobal::song->addUndo(MusECore::UndoOp(MusECore::UndoOp::ModifyTrackChannel, 
+                  MusEGlobal::song->applyOperation(MusECore::UndoOp(MusECore::UndoOp::ModifyTrackChannel, 
                                                               editTrack, 
                                                               at->channels(), 
                                                               n));
-                  MusEGlobal::audio->msgSetChannels(at, n);
-                  MusEGlobal::song->endUndo(SC_CHANNELS);
             }
           }       
         }         
@@ -723,7 +713,7 @@ void TList::ctrlValueFinished()
         {
           if (p->second->tick()==0)
           {
-            for (MusECore::iEvent ev=p->second->events()->begin(); ev!=p->second->events()->end(); ev++)
+            for (MusECore::ciEvent ev=p->second->events().begin(); ev!=p->second->events().end(); ev++)
             {
               if (ev->second.tick()!=0) break;
               else if (ev->second.type()==MusECore::Controller && ev->second.dataA()==ctrl_num)
@@ -1962,8 +1952,7 @@ void TList::mousePressEvent(QMouseEvent* ev)
                               {
                                 switch (n) {
                                     case 1001:     // delete track
-                                          MusEGlobal::song->removeTrack0(t);
-                                          MusEGlobal::audio->msgUpdateSoloStates();
+                                          MusEGlobal::song->applyOperation(UndoOp(UndoOp::DeleteTrack, MusEGlobal::song->tracks()->index(t), t));
                                           break;
 
                                     case 1002:     // show track comment
@@ -2150,7 +2139,7 @@ void TList::mousePressEvent(QMouseEvent* ev)
                           {
                             if (p->second->tick()==0)
                             {
-                              for (MusECore::iEvent ev=p->second->events()->begin(); ev!=p->second->events()->end(); ev++)
+                              for (MusECore::ciEvent ev=p->second->events().begin(); ev!=p->second->events().end(); ev++)
                               {
                                 if (ev->second.tick()!=0) break;
                                 else if (ev->second.type()==MusECore::Controller && ev->second.dataA()==ctrl_num)
@@ -2510,185 +2499,6 @@ void TList::mouseReleaseEvent(QMouseEvent* ev)
 void TList::wheelEvent(QWheelEvent* ev)
       {
         emit redirectWheelEvent(ev);
-            
-// REMOVE Tim. Hate to just kill all this, so remove later if all tests OK.
-//       int x           = ev->x();
-//       int y           = ev->y();
-//       MusECore::Track* t        = y2Track(y + ypos);
-//       if (t == 0) {
-//            emit redirectWheelEvent(ev);
-//            return;
-//             }
-//
-//       TrackColumn col = TrackColumn(header->logicalIndexAt(x));
-//       int delta       = ev->delta() / WHEEL_DELTA;
-//       ev->accept();
-// 
-//       switch (col) {
-//             case COL_RECORD:
-//             case COL_NONE:
-//             case COL_CLASS:
-//             case COL_NAME:
-//             case COL_AUTOMATION:
-//                   break;
-//             case COL_MUTE:
-//                   // p3.3.29
-//                   if (((QInputEvent*)ev)->modifiers() & Qt::ShiftModifier)
-//                     t->setOff(!t->off());
-//                   else
-//                   {
-//                     if (t->off())
-//                           t->setOff(false);
-//                     else
-//                           t->setMute(!t->mute());
-//                   }        
-//                   MusEGlobal::song->update(SC_MUTE);
-//                   break;
-// 
-//             case COL_SOLO:
-//                   MusEGlobal::audio->msgSetSolo(t, !t->solo());
-//                   MusEGlobal::song->update(SC_SOLO);
-//                   break;
-// 
-//             case COL_TIMELOCK:
-//                   t->setLocked(!t->locked());
-//                   break;
-// 
-//             case COL_OPORT:
-//                   if (t->isMidiTrack()) {
-//                         MusECore::MidiTrack* mt = (MusECore::MidiTrack*)t;
-//                         int port = mt->outPort() + delta;
-// 
-//                         if (port >= MIDI_PORTS)
-//                               port = MIDI_PORTS-1;
-//                         else if (port < 0)
-//                               port = 0;
-//                         if (port != ((MusECore::MidiTrack*)t)->outPort()) {
-//                               MusEGlobal::audio->msgIdle(true);
-//                               mt->setOutPortAndUpdate(port);
-//                               MusEGlobal::audio->msgIdle(false);
-//                               
-//                               MusEGlobal::audio->msgUpdateSoloStates();     // p4.0.14
-//                               MusEGlobal::song->update(SC_MIDI_TRACK_PROP); // p4.0.17
-//                               }
-//                         }
-//                   break;
-// 
-//             case COL_OCHANNEL:
-//                   if (t->isMidiTrack()) {
-//                         MusECore::MidiTrack* mt = (MusECore::MidiTrack*)t;
-//                         if (mt && mt->type() == MusECore::Track::DRUM)
-//                             break;
-// 
-//                         int channel = mt->outChannel() + delta;
-// 
-//                         if (channel >= MIDI_CHANNELS)
-//                               channel = MIDI_CHANNELS-1;
-//                         else if (channel < 0)
-//                               channel = 0;
-//                         if (channel != ((MusECore::MidiTrack*)t)->outChannel()) {
-//                               MusEGlobal::audio->msgIdle(true);
-//                               mt->setOutChanAndUpdate(channel);
-//                               MusEGlobal::audio->msgIdle(false);
-//                               
-//                               // may result in adding/removing mixer strip:
-//                               //MusEGlobal::song->update(-1);
-//                               MusEGlobal::audio->msgUpdateSoloStates();         // p4.0.14
-//                               MusEGlobal::song->update(SC_MIDI_TRACK_PROP);     
-//                               }
-//                         }
-//                   else {
-//                         int n = t->channels() + delta;
-//                         if (n > MAX_CHANNELS)
-//                               n = MAX_CHANNELS;
-//                         else if (n < 1)
-//                               n = 1;
-//                         if (n != t->channels()) {
-//                               MusEGlobal::audio->msgSetChannels((MusECore::AudioTrack*)t, n);
-//                               MusEGlobal::song->update(SC_CHANNELS);
-//                               }
-//                         }
-//                   break;
-//             default:
-//                   if (col>=COL_CUSTOM_MIDICTRL_OFFSET)
-//                   {
-//                     mode = START_DRAG;
-// 
-//                     if (t->isMidiTrack()) 
-//                     {
-//                       MusECore::MidiTrack* mt = dynamic_cast<MusECore::MidiTrack*>(t);
-//                       if (mt == 0)
-//                         break;
-//                       
-//                       int ctrl_num = Arranger::custom_columns[col-COL_CUSTOM_MIDICTRL_OFFSET].ctrl;
-//                       
-//                       MusECore::MidiPort* mp = &MusEGlobal::midiPorts[mt->outPort()];
-//                       MusECore::MidiController* mctl = mp->midiController(ctrl_num);
-//                       
-//                       int minval=mctl->minVal()+mctl->bias();
-//                       int maxval=mctl->maxVal()+mctl->bias();
-// 
-//                       int val = mt->getControllerChangeAtTick(0,ctrl_num);
-//                       int oldval=val;
-// 
-//                       if (ctrl_num!=MusECore::CTRL_PROGRAM)
-//                       {
-//                         val += delta;
-//                         if(val > maxval)
-//                           val = maxval;
-//                         if(val < minval-1) // "-1" because of "off"
-//                           val = minval-1;
-//                       }
-//                       else
-//                       {
-//                         MusECore::MidiInstrument* instr = mp->instrument();
-//                         if (delta>0) val=instr->getNextPatch(mt->outChannel(), val, false); 
-//                         else if (delta<0) val=instr->getPrevPatch(mt->outChannel(), val, false);
-//                       }
-// 
-//                       if (val != oldval)
-//                       {
-//                         if (val!=minval-1)
-//                         {
-//                           int at_tick;
-//                           if (Arranger::custom_columns[col-COL_CUSTOM_MIDICTRL_OFFSET].affected_pos ==
-//                               Arranger::custom_col_t::AFFECT_BEGIN)
-//                             at_tick=0;
-//                           else
-//                             at_tick=MusEGlobal::song->cpos();
-//                           
-//                           record_controller_change_and_maybe_send(at_tick, ctrl_num, val, mt);
-//                         }
-//                         else
-//                         {
-//                           MusECore::Undo operations;
-//                           for (MusECore::iPart p = mt->parts()->begin(); p!=mt->parts()->end(); p++)
-//                           {
-//                             if (p->second->tick()==0)
-//                             {
-//                               for (MusECore::iEvent ev=p->second->events()->begin(); ev!=p->second->events()->end(); ev++)
-//                               {
-//                                 if (ev->second.tick()!=0) break;
-//                                 else if (ev->second.type()==MusECore::Controller && ev->second.dataA()==ctrl_num)
-//                                 {
-//                                   using MusECore::UndoOp;
-//                                   operations.push_back(UndoOp(UndoOp::DeleteEvent, ev->second, p->second, false, false));
-//                                   break;
-//                                 }
-//                               }
-//                             }
-//                           }
-//                           MusEGlobal::song->applyOperationGroup(operations);
-//                         }
-//                       }
-//                     }
-//                   }
-//                   else
-//                       mode = START_DRAG;
-// 
-//                   break;
-//             }
-            
       }
 
 
@@ -2729,8 +2539,7 @@ void TList::classesPopupMenu(MusECore::Track* t, int x, int y)
             MusECore::PartList* pl = t->parts();
             MusECore::MidiTrack* m = (MusECore::MidiTrack*) t;
             for (MusECore::iPart ip = pl->begin(); ip != pl->end(); ++ip) {
-                  MusECore::EventList* el = ip->second->events();
-                  for (MusECore::iEvent ie = el->begin(); ie != el->end(); ++ie) {
+                  for (MusECore::ciEvent ie = ip->second->events().begin(); ie != ip->second->events().end(); ++ie) {
                         MusECore::Event ev = ie->second;
                         if(ev.type() == MusECore::Note)
                         {
@@ -2769,8 +2578,7 @@ void TList::classesPopupMenu(MusECore::Track* t, int x, int y)
             MusECore::PartList* pl = t->parts();
             MusECore::MidiTrack* m = (MusECore::MidiTrack*) t;
             for (MusECore::iPart ip = pl->begin(); ip != pl->end(); ++ip) {
-                  MusECore::EventList* el = ip->second->events();
-                  for (MusECore::iEvent ie = el->begin(); ie != el->end(); ++ie) {
+                  for (MusECore::ciEvent ie = ip->second->events().begin(); ie != ip->second->events().end(); ++ie) {
                         MusECore::Event ev = ie->second;
                         if (ev.type() == MusECore::Note)
                         {
diff --git a/muse2/muse/audio.cpp b/muse2/muse/audio.cpp
index 0c507fa2..f399a24c 100644
--- a/muse2/muse/audio.cpp
+++ b/muse2/muse/audio.cpp
@@ -76,36 +76,22 @@ void initAudio()
 extern double curTime();
 
 const char* seqMsgList[] = {
-      "SEQM_ADD_TRACK", "SEQM_REMOVE_TRACK", //"SEQM_CHANGE_TRACK",   DELETETHIS
-      "SEQM_MOVE_TRACK",
-      "SEQM_ADD_PART", "SEQM_REMOVE_PART", "SEQM_CHANGE_PART",
-      "SEQM_ADD_EVENT", "SEQM_REMOVE_EVENT", "SEQM_CHANGE_EVENT",
       "SEQM_ADD_TEMPO", "SEQM_SET_TEMPO", "SEQM_REMOVE_TEMPO", "SEQM_ADD_SIG", "SEQM_REMOVE_SIG",
+      "SEQM_ADD_KEY", "SEQM_REMOVE_KEY",
       "SEQM_SET_GLOBAL_TEMPO",
-      "SEQM_UNDO", "SEQM_REDO",
+      "SEQM_REVERT_OPERATION_GROUP", "SEQM_EXECUTE_OPERATION_GROUP",
       "SEQM_RESET_DEVICES", "SEQM_INIT_DEVICES", "SEQM_PANIC",
       "SEQM_MIDI_LOCAL_OFF",
-      "SEQM_SET_MIDI_DEVICE",
       "SEQM_PLAY_MIDI_EVENT",
       "SEQM_SET_HW_CTRL_STATE",
       "SEQM_SET_HW_CTRL_STATES",
-      "SEQM_SET_TRACK_OUT_PORT",
-      "SEQM_SET_TRACK_OUT_CHAN",
       "SEQM_SET_TRACK_AUTO_TYPE",
-      "SEQM_REMAP_PORT_DRUM_CTL_EVS",
-      "SEQM_CHANGE_ALL_PORT_DRUM_CTL_EVS",
-      "SEQM_SCAN_ALSA_MIDI_PORTS",
       "SEQM_SET_AUX",
       "SEQM_UPDATE_SOLO_STATES",
-      //"MIDI_SHOW_INSTR_GUI", DELETETHIS
-      //"MIDI_SHOW_INSTR_NATIVE_GUI", DELETETHIS
       "AUDIO_RECORD",
       "AUDIO_ROUTEADD", "AUDIO_ROUTEREMOVE", "AUDIO_REMOVEROUTES",
-      //"AUDIO_VOL", "AUDIO_PAN", DELETETHIS
       "AUDIO_ADDPLUGIN",
-      "AUDIO_SET_SEG_SIZE",
       "AUDIO_SET_PREFADER", "AUDIO_SET_CHANNELS",
-      //"AUDIO_SET_PLUGIN_CTRL_VAL", DELETETHIS
       "AUDIO_SWAP_CONTROLLER_IDX",
       "AUDIO_CLEAR_CONTROLLER_EVENTS",
       "AUDIO_SEEK_PREV_AC_EVENT",
@@ -688,17 +674,6 @@ void Audio::processMsg(AudioMsg* msg)
                   MusEGlobal::midiLearnCtrl = -1;
                   break;
             
-            case AUDIO_SET_SEG_SIZE:
-                  MusEGlobal::segmentSize = msg->ival;
-                  MusEGlobal::sampleRate  = msg->iival;
-#if 0 //TODO or DELETETHIS ?
-                  audioOutput.MusEGlobal::segmentSizeChanged();
-                  for (int i = 0; i < mixerGroups; ++i)
-                        audioGroups[i].MusEGlobal::segmentSizeChanged();
-                  for (iSynthI ii = synthiInstances.begin(); ii != synthiInstances.end();++ii)
-                        (*ii)->MusEGlobal::segmentSizeChanged();
-#endif
-                  break;
 
             case SEQM_RESET_DEVICES:
                   for (int i = 0; i < MIDI_PORTS; ++i)                         
@@ -735,16 +710,6 @@ void Audio::processMsg(AudioMsg* msg)
                   port->setHwCtrlStates(msg->a, msg->b, msg->c, msg->ival);
                   }
                   break;
-            case SEQM_SCAN_ALSA_MIDI_PORTS:
-                  alsaScanMidiPorts();
-                  break;
-            //DELETETHIS 6
-            //case MIDI_SHOW_INSTR_GUI:
-            //      MusEGlobal::midiSeq->msgUpdatePollFd();
-            //      break;
-            //case MIDI_SHOW_INSTR_NATIVE_GUI:   
-            //      MusEGlobal::midiSeq->msgUpdatePollFd();
-            //      break;
             case SEQM_ADD_TEMPO:
             case SEQM_REMOVE_TEMPO:
             case SEQM_SET_GLOBAL_TEMPO:
@@ -762,19 +727,6 @@ void Audio::processMsg(AudioMsg* msg)
                         frameOffset   = syncFrame - samplePos;
                         }
                   break;
-            // DELETETHIS 6
-            //case SEQM_ADD_TRACK:
-            //case SEQM_REMOVE_TRACK:
-            //case SEQM_CHANGE_TRACK:
-            //case SEQM_ADD_PART:
-            //case SEQM_REMOVE_PART:
-            //case SEQM_CHANGE_PART:
-            case SEQM_SET_TRACK_OUT_CHAN:
-            case SEQM_SET_TRACK_OUT_PORT:
-            case SEQM_REMAP_PORT_DRUM_CTL_EVS:
-            case SEQM_CHANGE_ALL_PORT_DRUM_CTL_EVS:
-                  MusEGlobal::midiSeq->sendMsg(msg);
-                  break;
 
             case SEQM_SET_TRACK_AUTO_TYPE:
                   msg->track->setAutomationType(AutomationType(msg->ival));
@@ -1034,19 +986,17 @@ void Audio::recordStop()
       MidiTrackList* ml = MusEGlobal::song->midis();
       for (iMidiTrack it = ml->begin(); it != ml->end(); ++it) {
             MidiTrack* mt     = *it;
-            MPEventList* mpel = mt->mpevents();
-            EventList* el     = mt->events();
 
             //---------------------------------------------------
             //    resolve NoteOff events, Controller etc.
             //---------------------------------------------------
 
             // Do SysexMeta. Do loops.
-            buildMidiEventList(el, mpel, mt, MusEGlobal::config.division, true, true);
-            MusEGlobal::song->cmdAddRecordedEvents(mt, el, 
+            buildMidiEventList(&mt->events, mt->mpevents, mt, MusEGlobal::config.division, true, true);
+            MusEGlobal::song->cmdAddRecordedEvents(mt, mt->events, 
                  MusEGlobal::extSyncFlag.value() ? startExternalRecTick : startRecordPos.tick());
-            el->clear();
-            mpel->clear();
+            mt->events.clear();
+            mt->mpevents.clear();
             }
       
       //
diff --git a/muse2/muse/audio.h b/muse2/muse/audio.h
index a403e5bf..e1a90485 100644
--- a/muse2/muse/audio.h
+++ b/muse2/muse/audio.h
@@ -52,6 +52,7 @@ class Part;
 class PluginI;
 class SynthI;
 class Track;
+class Undo;
 
 //---------------------------------------------------------
 //   AudioMsgId
@@ -60,37 +61,22 @@ class Track;
 //---------------------------------------------------------
 
 enum {
-      SEQM_ADD_TRACK, SEQM_REMOVE_TRACK,   //SEQM_CHANGE_TRACK,   DELETETHIS
-      SEQM_MOVE_TRACK,
-      SEQM_ADD_PART, SEQM_REMOVE_PART, SEQM_CHANGE_PART,
-      SEQM_ADD_EVENT, SEQM_REMOVE_EVENT, SEQM_CHANGE_EVENT,
       SEQM_ADD_TEMPO, SEQM_SET_TEMPO, SEQM_REMOVE_TEMPO, SEQM_ADD_SIG, SEQM_REMOVE_SIG,
       SEQM_ADD_KEY, SEQM_REMOVE_KEY,
       SEQM_SET_GLOBAL_TEMPO,
-      SEQM_UNDO, SEQM_REDO,
+      SEQM_REVERT_OPERATION_GROUP, SEQM_EXECUTE_OPERATION_GROUP,
       SEQM_RESET_DEVICES, SEQM_INIT_DEVICES, SEQM_PANIC,
       SEQM_MIDI_LOCAL_OFF,
-      SEQM_SET_MIDI_DEVICE,
       SEQM_PLAY_MIDI_EVENT,
       SEQM_SET_HW_CTRL_STATE,
       SEQM_SET_HW_CTRL_STATES,
-      SEQM_SET_TRACK_OUT_PORT,
-      SEQM_SET_TRACK_OUT_CHAN,
       SEQM_SET_TRACK_AUTO_TYPE,
-      SEQM_REMAP_PORT_DRUM_CTL_EVS,
-      SEQM_CHANGE_ALL_PORT_DRUM_CTL_EVS,
-      SEQM_SCAN_ALSA_MIDI_PORTS,
       SEQM_SET_AUX,
       SEQM_UPDATE_SOLO_STATES,
-      //MIDI_SHOW_INSTR_GUI,  DELETETHIS
-      //MIDI_SHOW_INSTR_NATIVE_GUI, DELETETHIS
       AUDIO_RECORD,
       AUDIO_ROUTEADD, AUDIO_ROUTEREMOVE, AUDIO_REMOVEROUTES,
-      //AUDIO_VOL, AUDIO_PAN,  DELETETHIS
       AUDIO_ADDPLUGIN,
-      AUDIO_SET_SEG_SIZE,
       AUDIO_SET_PREFADER, AUDIO_SET_CHANNELS,
-      //AUDIO_SET_PLUGIN_CTRL_VAL,  DELETETHIS
       AUDIO_SWAP_CONTROLLER_IDX,
       AUDIO_CLEAR_CONTROLLER_EVENTS,
       AUDIO_SEEK_PREV_AC_EVENT,
@@ -132,6 +118,7 @@ struct AudioMsg : public ThreadMsg {   // this should be an union
       char port, channel, ctrl;
       int a, b, c;
       Pos pos;
+      Undo* operations;
       };
 
 class AudioOutput;
@@ -232,29 +219,27 @@ class Audio {
       void msgSeek(const Pos&);
       void msgPlay(bool val);
 
-      void msgRemoveTrack(Track*, bool u = true);
+      void msgExecuteOperationGroup(Undo&); // calls exe1, then calls exe2 in audio context, then calls exe3
+      void msgRevertOperationGroup(Undo&); // similar.
+
       void msgRemoveTracks();
-      //void msgChangeTrack(Track* oldTrack, Track* newTrack, bool u = true); DELETETHIS
-      void msgMoveTrack(int idx1, int dx2, bool u = true);
-      void msgAddPart(Part*, bool u = true);
-      void msgRemovePart(Part*, bool u = true);
-      void msgChangePart(Part* oldPart, Part* newPart, bool u = true, bool doCtrls = true, bool doClones = false);
-      void msgAddEvent(Event&, Part*, bool u = true, bool doCtrls = true, bool doClones = false);
-      void msgDeleteEvent(Event&, Part*, bool u = true, bool doCtrls = true, bool doClones = false);
-      void msgChangeEvent(Event&, Event&, Part*, bool u = true, bool doCtrls = true, bool doClones = false);
-      void msgScanAlsaMidiPorts();
-      void msgAddTempo(int tick, int tempo, bool doUndoFlag = true);
-      void msgSetTempo(int tick, int tempo, bool doUndoFlag = true);
-      void msgUpdateSoloStates();
+      void msgRemoveTrack(Track*, bool u = true); // only does applyOperation
+      void msgMoveTrack(int idx1, int dx2, bool u = true); // only does applyOperation
+      void msgAddPart(Part*, bool u = true); // only does applyOperation
+      void msgRemovePart(Part*, bool u = true); // only does applyOperation
+      void msgAddEvent(Event&, Part*, bool u = true, bool doCtrls = true, bool doClones = false); // only does applyOperation
+      void msgDeleteEvent(Event&, Part*, bool u = true, bool doCtrls = true, bool doClones = false); // only does applyOperation
+      void msgChangeEvent(Event&, Event&, Part*, bool u = true, bool doCtrls = true, bool doClones = false); // only does applyOperation
+      void msgAddTempo(int tick, int tempo, bool doUndoFlag = true); // only does applyOperation
+      void msgSetTempo(int tick, int tempo, bool doUndoFlag = true); // FIXME FINDMICHJETZT TODO!
+      void msgDeleteTempo(int tick, int tempo, bool doUndoFlag = true); // only does applyOperation
+      void msgUpdateSoloStates(); // TODO and below
       void msgSetAux(AudioTrack*, int, double);
       void msgSetGlobalTempo(int val);
-      void msgDeleteTempo(int tick, int tempo, bool doUndoFlag = true);
       void msgAddSig(int tick, int z, int n, bool doUndoFlag = true);
       void msgRemoveSig(int tick, int z, int n, bool doUndoFlag = true);
       void msgAddKey(int tick, int key, bool doUndoFlag = true);
       void msgRemoveKey(int tick, int key, bool doUndoFlag = true);
-      //void msgShowInstrumentGui(MidiInstrument*, bool);   DELETETHIS
-      //void msgShowInstrumentNativeGui(MidiInstrument*, bool);  DELETETHIS
       void msgPanic();
       void sendMsg(AudioMsg*);
       bool sendMessage(AudioMsg* m, bool doUndo);
@@ -265,24 +250,14 @@ class Audio {
       void msgAddRoute(Route, Route);
       void msgAddRoute1(Route, Route);
       void msgAddPlugin(AudioTrack*, int idx, PluginI* plugin);
-      void msgSetMute(AudioTrack*, bool val);
-      //void msgSetVolume(AudioTrack*, double val); DELETETHIS
-      //void msgSetPan(AudioTrack*, double val);    DELETETHIS
-      void msgAddSynthI(SynthI* synth);
-      void msgRemoveSynthI(SynthI* synth);
-      void msgSetSegSize(int, int);
       void msgSetPrefader(AudioTrack*, int);
       void msgSetChannels(AudioTrack*, int);
-      void msgSetOff(AudioTrack*, bool);
       void msgSetRecord(AudioTrack*, bool);
-      void msgUndo();
-      void msgRedo();
       void msgLocalOff();
       void msgInitMidiDevices(bool force = true);
       void msgResetMidiDevices();
       void msgIdle(bool);
       void msgBounce();
-      //void msgSetPluginCtrlVal(AudioTrack*, int /*param*/, double /*val*/);  DELETETHIS
       void msgSwapControllerIDX(AudioTrack*, int, int);
       void msgClearControllerEvents(AudioTrack*, int);
       void msgSeekPrevACEvent(AudioTrack*, int);
@@ -294,17 +269,11 @@ class Audio {
       void msgSetSolo(Track*, bool);
       void msgSetHwCtrlState(MidiPort*, int, int, int);
       void msgSetHwCtrlStates(MidiPort*, int, int, int, int);
-      void msgSetTrackOutChannel(MidiTrack*, int);
-      void msgSetTrackOutPort(MidiTrack*, int);
       void msgSetTrackAutomationType(Track*, int);
-      void msgRemapPortDrumCtlEvents(int, int, int, int);
-      void msgChangeAllPortDrumCtrlEvents(bool, bool);
       void msgSetSendMetronome(AudioTrack*, bool);
       void msgStartMidiLearn();
-
       void msgPlayMidiEvent(const MidiPlayEvent* event);
-      void rescanAlsaPorts();
-
+      
       void midiPortsChanged();
 
       const Pos& pos() const { return _pos; }
diff --git a/muse2/muse/ctrl/ctrlcanvas.cpp b/muse2/muse/ctrl/ctrlcanvas.cpp
index d5adbc4f..8dd7fa9a 100644
--- a/muse2/muse/ctrl/ctrlcanvas.cpp
+++ b/muse2/muse/ctrl/ctrlcanvas.cpp
@@ -608,14 +608,13 @@ void CtrlCanvas::updateItems()
               if (filterTrack && part->track() != curTrack)
                 continue;
               
-              MusECore::EventList* el = part->events();
               MusECore::MidiCtrlValList* mcvl;
               partControllers(part, _cnum, 0, 0, 0, &mcvl);
               unsigned len = part->lenTick();
 
-              for (MusECore::iEvent i = el->begin(); i != el->end(); ++i) 
+              for (MusECore::ciEvent i = part->events().begin(); i != part->events().end(); ++i) 
               {
-                    MusECore::Event e = i->second;
+                    const MusECore::Event& e = i->second;
                     // Do not add events which are past the end of the part.
                     if(e.tick() >= len)
                       break;
diff --git a/muse2/muse/event.cpp b/muse2/muse/event.cpp
index 1a2d3c6e..32b72277 100644
--- a/muse2/muse/event.cpp
+++ b/muse2/muse/event.cpp
@@ -74,7 +74,7 @@ void EventBase::dump(int n) const
 //   clone
 //---------------------------------------------------------
 
-Event Event::clone()
+Event Event::clone() const
       {
       #ifdef USE_SAMPLERATE
       return Event(ev->clone(), _audConv);
@@ -179,6 +179,10 @@ Event& Event::operator=(const Event& e) {
 bool Event::operator==(const Event& e) const {
             return ev == e.ev;
             }
+bool Event::isSimilarTo(const Event& other) const
+{
+		return ev->isSimilarTo(*other.ev);
+}
 
 int Event::getRefCount() const    { return ev->getRefCount(); }
 bool Event::selected() const      { return ev->_selected; }
@@ -203,7 +207,7 @@ void Event::read(Xml& xml)
 
 void Event::write(int a, Xml& xml, const Pos& o, bool forceWavePaths) const { ev->write(a, xml, o, forceWavePaths); }
 void Event::dump(int n) const     { ev->dump(n); }
-Event Event::mid(unsigned a, unsigned b) { return Event(ev->mid(a, b)); }
+Event Event::mid(unsigned a, unsigned b) const { return Event(ev->mid(a, b)); }
 
 bool Event::isNote() const                   { return ev->isNote();        }
 bool Event::isNoteOff() const                { return ev->isNoteOff();     }
diff --git a/muse2/muse/event.h b/muse2/muse/event.h
index 8da37d4f..b2f5a50a 100644
--- a/muse2/muse/event.h
+++ b/muse2/muse/event.h
@@ -64,6 +64,7 @@ class Event {
       void setType(EventType t);
       Event& operator=(const Event& e);
       bool operator==(const Event& e) const;
+      bool isSimilarTo(const Event& other) const;
 
       int getRefCount() const;
       bool selected() const;
@@ -73,8 +74,8 @@ class Event {
       void read(Xml& xml);
       void write(int a, Xml& xml, const Pos& offset, bool ForceWavePaths = false) const;
       void dump(int n = 0) const;
-      Event clone();
-      Event mid(unsigned a, unsigned b);
+      Event clone() const;
+      Event mid(unsigned a, unsigned b) const;
 
       bool isNote() const;
       bool isNoteOff() const;
@@ -124,7 +125,7 @@ typedef std::multimap <unsigned, Event, std::less<unsigned> > EL;
 typedef EL::iterator iEvent;
 typedef EL::reverse_iterator riEvent;
 typedef EL::const_iterator ciEvent;
-typedef std::pair <iEvent, iEvent> EventRange;
+typedef std::pair <ciEvent, ciEvent> EventRange;
 
 //---------------------------------------------------------
 //   EventList
@@ -132,21 +133,14 @@ typedef std::pair <iEvent, iEvent> EventRange;
 //---------------------------------------------------------
 
 class EventList : public EL {
-      int ref;          // number of references to this EventList
-      int aref;         // number of active references (exclude undo list)
       void deselect();
 
    public:
-      EventList()           { ref = 0; aref = 0;  }
-      ~EventList()          {}
-
-      void incRef(int n)    { ref += n;    }
-      int refCount() const  { return ref;  }
-      void incARef(int n)   { aref += n;   }
-      int arefCount() const { return aref; }
-
+      ciEvent find(const Event&) const;
       iEvent find(const Event&);
-      iEvent add(Event& event);
+      ciEvent findSimilar(const Event&) const;
+      iEvent findSimilar(const Event&);
+      iEvent add(Event event);
       void move(Event& event, unsigned tick);
       void dump() const;
       void read(Xml& xml, const char* name, bool midi);
diff --git a/muse2/muse/eventbase.h b/muse2/muse/eventbase.h
index 0cb960d9..92e91761 100644
--- a/muse2/muse/eventbase.h
+++ b/muse2/muse/eventbase.h
@@ -56,11 +56,13 @@ class EventBase : public PosLen {
       void setSelected(bool val) { _selected = val; }
 
       void move(int offset);
+      
+      virtual bool isSimilarTo(const EventBase& other) const = 0;
 
       virtual void read(Xml&) = 0;
       virtual void write(int, Xml&, const Pos& offset, bool forcePath = false) const = 0;
       virtual void dump(int n = 0) const;
-      virtual EventBase* mid(unsigned, unsigned) = 0;
+      virtual EventBase* mid(unsigned, unsigned) const = 0;
       friend class Event;
 
       virtual bool isNote() const                   { return false; }
@@ -95,7 +97,7 @@ class EventBase : public PosLen {
       virtual void setSpos(int)                     { }
       virtual SndFileR sndFile() const              { return 0;      }
       virtual void setSndFile(SndFileR&)            { }
-      virtual EventBase* clone() = 0;
+      virtual EventBase* clone() const = 0;
       
       virtual void readAudio(WavePart* /*part*/, unsigned /*offset*/, 
                              float** /*bpp*/, int /*channels*/, int /*nn*/, bool /*doSeek*/, bool /*overwrite*/) { }
diff --git a/muse2/muse/eventlist.cpp b/muse2/muse/eventlist.cpp
index 50ba2652..80180ab7 100644
--- a/muse2/muse/eventlist.cpp
+++ b/muse2/muse/eventlist.cpp
@@ -62,7 +62,7 @@ void EventList::read(Xml& xml, const char* name, bool midi)
 //   add
 //---------------------------------------------------------
 
-iEvent EventList::add(Event& event)
+iEvent EventList::add(Event event)
       {
       // Changed by Tim. An event list containing wave events should be sorted by
       //  frames. WaveTrack::fetchData() relies on the sorting order, and
@@ -129,17 +129,51 @@ void EventList::move(Event& event, unsigned tick)
 //---------------------------------------------------------
 
 iEvent EventList::find(const Event& event)
+{
+      std::pair<iEvent,iEvent> range = equal_range(event.type() == Wave ? event.frame() : event.tick());
+
+      for (iEvent i = range.first; i != range.second; ++i) {
+            if (i->second == event)
+                  return i;
+            }
+      return end();
+}
+
+ciEvent EventList::find(const Event& event) const
       {
       EventRange range = equal_range(event.type() == Wave ? event.frame() : event.tick());
 
       
-      for (iEvent i = range.first; i != range.second; ++i) {
+      for (ciEvent i = range.first; i != range.second; ++i) {
             if (i->second == event)
                   return i;
             }
       return end();
       }
 
+iEvent EventList::findSimilar(const Event& event)
+{
+      std::pair<iEvent,iEvent> range = equal_range(event.type() == Wave ? event.frame() : event.tick());
+
+      for (iEvent i = range.first; i != range.second; ++i) {
+            if (i->second.isSimilarTo(event))
+                  return i;
+            }
+      return end();
+}
+
+ciEvent EventList::findSimilar(const Event& event) const
+      {
+      EventRange range = equal_range(event.type() == Wave ? event.frame() : event.tick());
+
+      
+      for (ciEvent i = range.first; i != range.second; ++i) {
+            if (i->second.isSimilarTo(event))
+                  return i;
+            }
+      return end();
+      }
+
 //---------------------------------------------------------
 //   dump
 //---------------------------------------------------------
diff --git a/muse2/muse/exportmidi.cpp b/muse2/muse/exportmidi.cpp
index e5cd74e1..34ac8983 100644
--- a/muse2/muse/exportmidi.cpp
+++ b/muse2/muse/exportmidi.cpp
@@ -131,11 +131,11 @@ static void addController(MPEventList* l, int tick, int port, int channel, int a
 //     track can be NULL meaning no concept of drum notes is allowed in init sequences.
 //---------------------------------------------------------
 
-static void addEventList(MusECore::EventList* evlist, MusECore::MPEventList* mpevlist, MusECore::MidiTrack* track, MusECore::Part* part, int port, int channel)
+static void addEventList(const MusECore::EventList& evlist, MusECore::MPEventList* mpevlist, MusECore::MidiTrack* track, MusECore::Part* part, int port, int channel)
 {      
-  for (MusECore::iEvent i = evlist->begin(); i != evlist->end(); ++i) 
+  for (MusECore::ciEvent i = evlist.begin(); i != evlist.end(); ++i) 
   {
-    MusECore::Event ev = i->second;
+    const MusECore::Event& ev = i->second;
     int tick = ev.tick();
     if(part)
       tick += part->tick();
@@ -490,7 +490,7 @@ void MusE::exportMidi()
                     {
                       MusECore::EventList* el = instr->midiInit();
                       if(!el->empty())
-                        MusECore::addEventList(el, l, NULL, NULL, port, channel); // No track or part passed for init sequences
+                        MusECore::addEventList(*el, l, NULL, NULL, port, channel); // No track or part passed for init sequences
                     }
                     
                     //--------------------------
@@ -519,8 +519,7 @@ void MusE::exportMidi()
             MusECore::PartList* parts = track->parts();
             for (MusECore::iPart p = parts->begin(); p != parts->end(); ++p) {
                   MusECore::MidiPart* part    = (MusECore::MidiPart*) (p->second);
-                  MusECore::EventList* evlist = part->events();
-                  MusECore::addEventList(evlist, l, track, part, port, channel); 
+                  MusECore::addEventList(part->events(), l, track, part, port, channel); 
                   }
                   
             ++i;  
@@ -529,12 +528,7 @@ void MusE::exportMidi()
       mf.setDivision(MusEGlobal::config.midiDivision);
       mf.setTrackList(mtl, i);
       mf.write();
-      
-      // DELETETHIS 4 ??? or is this still an issue?
-      // TESTING: Cleanup. I did not valgrind this feature in last memleak fixes, but I suspect it leaked. 
-      //for(MusECore::iMidiFileTrack imft = mtl->begin(); imft != mtl->end(); ++imft)
-      //  delete *imft;
-      //delete mtl;
+
       }
 
 } // namespace MusEGui
diff --git a/muse2/muse/functions.cpp b/muse2/muse/functions.cpp
index fa53f5d4..7569cc95 100644
--- a/muse2/muse/functions.cpp
+++ b/muse2/muse/functions.cpp
@@ -2,7 +2,7 @@
 //  MusE
 //  Linux Music Editor
 //    $Id: functions.cpp,v 1.20.2.19 2011/05/05 20:10 flo93 Exp $
-//  (C) Copyright 2011 Florian Jung (flo93@sourceforge.net)
+//  (C) Copyright 2011,2013 Florian Jung (flo93@sourceforge.net)
 //
 //  This program is free software; you can redistribute it and/or
 //  modify it under the terms of the GNU General Public License
@@ -71,9 +71,9 @@ bool read_eventlist_and_part(Xml& xml, EventList* el, int* part_id);
 
 
 
-set<Part*> partlist_to_set(PartList* pl)
+set<const Part*> partlist_to_set(PartList* pl)
 {
-	set<Part*> result;
+	set<const Part*> result;
 	
 	for (PartList::iterator it=pl->begin(); it!=pl->end(); it++)
 		result.insert(it->second);
@@ -81,16 +81,16 @@ set<Part*> partlist_to_set(PartList* pl)
 	return result;
 }
 
-set<Part*> part_to_set(Part* p)
+set<const Part*> part_to_set(const Part* p)
 {
-	set<Part*> result;
+	set<const Part*> result;
 	result.insert(p);
 	return result;
 }
 
-set<Part*> get_all_parts()
+set<const Part*> get_all_parts()
 {
-	set<Part*> result;
+	set<const Part*> result;
 	
 	TrackList* tracks=MusEGlobal::song->tracks();
 	for (TrackList::const_iterator t_it=tracks->begin(); t_it!=tracks->end(); t_it++)
@@ -103,9 +103,9 @@ set<Part*> get_all_parts()
 	return result;
 }
 
-set<Part*> get_all_selected_parts()
+set<const Part*> get_all_selected_parts()
 {
-	set<Part*> result;
+	set<const Part*> result;
 	
 	TrackList* tracks=MusEGlobal::song->tracks();
 	for (TrackList::const_iterator t_it=tracks->begin(); t_it!=tracks->end(); t_it++)
@@ -137,14 +137,14 @@ bool is_relevant(const Event& event, const Part* part, int range)
 }
 
 
-map<Event*, Part*> get_events(const set<Part*>& parts, int range)
+map<const Event*, const Part*> get_events(const set<const Part*>& parts, int range)
 {
-	map<Event*, Part*> events;
+	map<const Event*, const Part*> events;
 	
-	for (set<Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
-		for (iEvent event=(*part)->events()->begin(); event!=(*part)->events()->end(); event++)
+	for (set<const Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
+		for (ciEvent event=(*part)->events().begin(); event!=(*part)->events().end(); event++)
 			if (is_relevant(event->second, *part, range))
-				events.insert(pair<Event*, Part*>(&event->second, *part));
+				events.insert(pair<const Event*, const Part*>(&event->second, *part));
 	
 	return events;
 }
@@ -152,7 +152,7 @@ map<Event*, Part*> get_events(const set<Part*>& parts, int range)
 
 
 
-bool modify_notelen(const set<Part*>& parts)
+bool modify_notelen(const set<const Part*>& parts)
 {
 	if (!MusEGui::gatetime_dialog->exec())
 		return false;
@@ -162,7 +162,7 @@ bool modify_notelen(const set<Part*>& parts)
 	return true;
 }
 
-bool modify_velocity(const set<Part*>& parts)
+bool modify_velocity(const set<const Part*>& parts)
 {
 	if (!MusEGui::velocity_dialog->exec())
 		return false;
@@ -172,7 +172,7 @@ bool modify_velocity(const set<Part*>& parts)
 	return true;
 }
 
-bool quantize_notes(const set<Part*>& parts)
+bool quantize_notes(const set<const Part*>& parts)
 {
 	if (!MusEGui::quantize_dialog->exec())
 		return false;
@@ -185,7 +185,7 @@ bool quantize_notes(const set<Part*>& parts)
 	return true;
 }
 
-bool erase_notes(const set<Part*>& parts)
+bool erase_notes(const set<const Part*>& parts)
 {
 	if (!MusEGui::erase_dialog->exec())
 		return false;
@@ -196,7 +196,7 @@ bool erase_notes(const set<Part*>& parts)
 	return true;
 }
 
-bool delete_overlaps(const set<Part*>& parts)
+bool delete_overlaps(const set<const Part*>& parts)
 {
 	if (!MusEGui::del_overlaps_dialog->exec())
 		return false;
@@ -206,7 +206,7 @@ bool delete_overlaps(const set<Part*>& parts)
 	return true;
 }
 
-bool set_notelen(const set<Part*>& parts)
+bool set_notelen(const set<const Part*>& parts)
 {
 	if (!MusEGui::set_notelen_dialog->exec())
 		return false;
@@ -216,7 +216,7 @@ bool set_notelen(const set<Part*>& parts)
 	return true;
 }
 
-bool move_notes(const set<Part*>& parts)
+bool move_notes(const set<const Part*>& parts)
 {
 	if (!MusEGui::move_notes_dialog->exec())
 		return false;
@@ -226,7 +226,7 @@ bool move_notes(const set<Part*>& parts)
 	return true;
 }
 
-bool transpose_notes(const set<Part*>& parts)
+bool transpose_notes(const set<const Part*>& parts)
 {
 	if (!MusEGui::transpose_dialog->exec())
 		return false;
@@ -236,7 +236,7 @@ bool transpose_notes(const set<Part*>& parts)
 	return true;
 }
 
-bool crescendo(const set<Part*>& parts)
+bool crescendo(const set<const Part*>& parts)
 {
 	if (MusEGlobal::song->rpos() <= MusEGlobal::song->lpos())
 	{
@@ -252,7 +252,7 @@ bool crescendo(const set<Part*>& parts)
 	return true;
 }
 
-bool legato(const set<Part*>& parts)
+bool legato(const set<const Part*>& parts)
 {
 	if (!MusEGui::legato_dialog->exec())
 		return false;
@@ -269,7 +269,7 @@ bool modify_notelen()
 	if (!MusEGui::gatetime_dialog->exec())
 		return false;
 		
-	set<Part*> parts;
+	set<const Part*> parts;
 	if (MusEGui::gatetime_dialog->range & FUNCTION_RANGE_ONLY_SELECTED)
 		parts=get_all_selected_parts();
 	else
@@ -285,7 +285,7 @@ bool modify_velocity()
 	if (!MusEGui::velocity_dialog->exec())
 		return false;
 		
-	set<Part*> parts;
+	set<const Part*> parts;
 	if (MusEGui::velocity_dialog->range & FUNCTION_RANGE_ONLY_SELECTED)
 		parts=get_all_selected_parts();
 	else
@@ -301,7 +301,7 @@ bool quantize_notes()
 	if (!MusEGui::quantize_dialog->exec())
 		return false;
 		
-	set<Part*> parts;
+	set<const Part*> parts;
 	if (MusEGui::quantize_dialog->range & FUNCTION_RANGE_ONLY_SELECTED)
 		parts=get_all_selected_parts();
 	else
@@ -320,7 +320,7 @@ bool erase_notes()
 	if (!MusEGui::erase_dialog->exec())
 		return false;
 		
-	set<Part*> parts;
+	set<const Part*> parts;
 	if (MusEGui::erase_dialog->range & FUNCTION_RANGE_ONLY_SELECTED)
 		parts=get_all_selected_parts();
 	else
@@ -337,7 +337,7 @@ bool delete_overlaps()
 	if (!MusEGui::del_overlaps_dialog->exec())
 		return false;
 		
-	set<Part*> parts;
+	set<const Part*> parts;
 	if (MusEGui::del_overlaps_dialog->range & FUNCTION_RANGE_ONLY_SELECTED)
 		parts=get_all_selected_parts();
 	else
@@ -353,7 +353,7 @@ bool set_notelen()
 	if (!MusEGui::set_notelen_dialog->exec())
 		return false;
 		
-	set<Part*> parts;
+	set<const Part*> parts;
 	if (MusEGui::set_notelen_dialog->range & FUNCTION_RANGE_ONLY_SELECTED)
 		parts=get_all_selected_parts();
 	else
@@ -369,7 +369,7 @@ bool move_notes()
 	if (!MusEGui::move_notes_dialog->exec())
 		return false;
 		
-	set<Part*> parts;
+	set<const Part*> parts;
 	if (MusEGui::move_notes_dialog->range & FUNCTION_RANGE_ONLY_SELECTED)
 		parts=get_all_selected_parts();
 	else
@@ -385,7 +385,7 @@ bool transpose_notes()
 	if (!MusEGui::transpose_dialog->exec())
 		return false;
 		
-	set<Part*> parts;
+	set<const Part*> parts;
 	if (MusEGui::transpose_dialog->range & FUNCTION_RANGE_ONLY_SELECTED)
 		parts=get_all_selected_parts();
 	else
@@ -407,7 +407,7 @@ bool crescendo()
 	if (!MusEGui::crescendo_dialog->exec())
 		return false;
 		
-	set<Part*> parts;
+	set<const Part*> parts;
 	if (MusEGui::crescendo_dialog->range & FUNCTION_RANGE_ONLY_SELECTED)
 		parts=get_all_selected_parts();
 	else
@@ -423,7 +423,7 @@ bool legato()
 	if (!MusEGui::legato_dialog->exec())
 		return false;
 		
-	set<Part*> parts;
+	set<const Part*> parts;
 	if (MusEGui::legato_dialog->range & FUNCTION_RANGE_ONLY_SELECTED)
 		parts=get_all_selected_parts();
 	else
@@ -439,17 +439,17 @@ bool legato()
 
 
 
-bool modify_velocity(const set<Part*>& parts, int range, int rate, int offset)
+bool modify_velocity(const set<const Part*>& parts, int range, int rate, int offset)
 {
-	map<Event*, Part*> events = get_events(parts, range);
+	map<const Event*, const Part*> events = get_events(parts, range);
 	Undo operations;
 	
 	if ( (!events.empty()) && ((rate!=100) || (offset!=0)) )
 	{
-		for (map<Event*, Part*>::iterator it=events.begin(); it!=events.end(); it++)
+		for (map<const Event*, const Part*>::iterator it=events.begin(); it!=events.end(); it++)
 		{
-			Event& event=*(it->first);
-			Part* part=it->second;
+			const Event& event=*(it->first);
+			const Part* part=it->second;
 			
 			int velo = event.velo();
 
@@ -475,17 +475,17 @@ bool modify_velocity(const set<Part*>& parts, int range, int rate, int offset)
 		return false;
 }
 
-bool modify_off_velocity(const set<Part*>& parts, int range, int rate, int offset)
+bool modify_off_velocity(const set<const Part*>& parts, int range, int rate, int offset)
 {
-	map<Event*, Part*> events = get_events(parts, range);
+	map<const Event*, const Part*> events = get_events(parts, range);
 	Undo operations;
 	
 	if ( (!events.empty()) && ((rate!=100) || (offset!=0)) )
 	{
-		for (map<Event*, Part*>::iterator it=events.begin(); it!=events.end(); it++)
+		for (map<const Event*, const Part*>::iterator it=events.begin(); it!=events.end(); it++)
 		{
-			Event& event=*(it->first);
-			Part* part=it->second;
+			const Event& event=*(it->first);
+			const Part* part=it->second;
 			
 			int velo = event.veloOff();
 
@@ -511,18 +511,18 @@ bool modify_off_velocity(const set<Part*>& parts, int range, int rate, int offse
 		return false;
 }
 
-bool modify_notelen(const set<Part*>& parts, int range, int rate, int offset)
+bool modify_notelen(const set<const Part*>& parts, int range, int rate, int offset)
 {
-	map<Event*, Part*> events = get_events(parts, range);
+	map<const Event*, const Part*> events = get_events(parts, range);
 	Undo operations;
-	map<Part*, int> partlen;
+	map<const Part*, int> partlen;
 	
 	if ( (!events.empty()) && ((rate!=100) || (offset!=0)) )
 	{
-		for (map<Event*, Part*>::iterator it=events.begin(); it!=events.end(); it++)
+		for (map<const Event*, const Part*>::iterator it=events.begin(); it!=events.end(); it++)
 		{
-			Event& event=*(it->first);
-			Part* part=it->second;
+			const Event& event=*(it->first);
+			const Part* part=it->second;
 
 			unsigned int len = event.lenTick(); //prevent compiler warning: comparison singed/unsigned
 
@@ -543,7 +543,7 @@ bool modify_notelen(const set<Part*>& parts, int range, int rate, int offset)
 			}
 		}
 		
-		for (map<Part*, int>::iterator it=partlen.begin(); it!=partlen.end(); it++)
+		for (map<const Part*, int>::iterator it=partlen.begin(); it!=partlen.end(); it++)
 			schedule_resize_all_same_len_clone_parts(it->first, it->second, operations);
 
 		return MusEGlobal::song->applyOperationGroup(operations);
@@ -552,7 +552,7 @@ bool modify_notelen(const set<Part*>& parts, int range, int rate, int offset)
 		return false;
 }
 
-bool set_notelen(const set<Part*>& parts, int range, int len)
+bool set_notelen(const set<const Part*>& parts, int range, int len)
 {
 	return modify_notelen(parts, range, 0, len);
 }
@@ -579,17 +579,17 @@ unsigned quantize_tick(unsigned tick, unsigned raster, int swing)
 		return tick_dest1;
 }
 
-bool quantize_notes(const set<Part*>& parts, int range, int raster, bool quant_len, int strength, int swing, int threshold)
+bool quantize_notes(const set<const Part*>& parts, int range, int raster, bool quant_len, int strength, int swing, int threshold)
 {
-	map<Event*, Part*> events = get_events(parts, range);
+	map<const Event*, const Part*> events = get_events(parts, range);
 	Undo operations;
 	
 	if (!events.empty())
 	{
-		for (map<Event*, Part*>::iterator it=events.begin(); it!=events.end(); it++)
+		for (map<const Event*, const Part*>::iterator it=events.begin(); it!=events.end(); it++)
 		{
-			Event& event=*(it->first);
-			Part* part=it->second;
+			const Event& event=*(it->first);
+			const Part* part=it->second;
 
 			unsigned begin_tick = event.tick() + part->tick();
 			int begin_diff = quantize_tick(begin_tick, raster, swing) - begin_tick;
@@ -625,17 +625,17 @@ bool quantize_notes(const set<Part*>& parts, int range, int raster, bool quant_l
 		return false;
 }
 
-bool erase_notes(const set<Part*>& parts, int range, int velo_threshold, bool velo_thres_used, int len_threshold, bool len_thres_used)
+bool erase_notes(const set<const Part*>& parts, int range, int velo_threshold, bool velo_thres_used, int len_threshold, bool len_thres_used)
 {
-	map<Event*, Part*> events = get_events(parts, range);
+	map<const Event*, const Part*> events = get_events(parts, range);
 	Undo operations;
 	
 	if (!events.empty())
 	{
-		for (map<Event*, Part*>::iterator it=events.begin(); it!=events.end(); it++)
+		for (map<const Event*, const Part*>::iterator it=events.begin(); it!=events.end(); it++)
 		{
-			Event& event=*(it->first);
-			Part* part=it->second;
+			const Event& event=*(it->first);
+			const Part* part=it->second;
 
 			if ( (!velo_thres_used && !len_thres_used) ||
 			     (velo_thres_used && event.velo() < velo_threshold) ||
@@ -649,17 +649,17 @@ bool erase_notes(const set<Part*>& parts, int range, int velo_threshold, bool ve
 		return false;
 }
 
-bool transpose_notes(const set<Part*>& parts, int range, signed int halftonesteps)
+bool transpose_notes(const set<const Part*>& parts, int range, signed int halftonesteps)
 {
-	map<Event*, Part*> events = get_events(parts, range);
+	map<const Event*, const Part*> events = get_events(parts, range);
 	Undo operations;
 	
 	if ( (!events.empty()) && (halftonesteps!=0) )
 	{
-		for (map<Event*, Part*>::iterator it=events.begin(); it!=events.end(); it++)
+		for (map<const Event*, const Part*>::iterator it=events.begin(); it!=events.end(); it++)
 		{
-			Event& event=*(it->first);
-			Part* part=it->second;
+			const Event& event=*(it->first);
+			const Part* part=it->second;
 
 			Event newEvent = event.clone();
 			int pitch = event.pitch()+halftonesteps;
@@ -675,9 +675,9 @@ bool transpose_notes(const set<Part*>& parts, int range, signed int halftonestep
 		return false;
 }
 
-bool crescendo(const set<Part*>& parts, int range, int start_val, int end_val, bool absolute)
+bool crescendo(const set<const Part*>& parts, int range, int start_val, int end_val, bool absolute)
 {
-	map<Event*, Part*> events = get_events(parts, range);
+	map<const Event*, const Part*> events = get_events(parts, range);
 	Undo operations;
 	
 	int from=MusEGlobal::song->lpos();
@@ -685,10 +685,10 @@ bool crescendo(const set<Part*>& parts, int range, int start_val, int end_val, b
 	
 	if ( (!events.empty()) && (to>from) )
 	{
-		for (map<Event*, Part*>::iterator it=events.begin(); it!=events.end(); it++)
+		for (map<const Event*, const Part*>::iterator it=events.begin(); it!=events.end(); it++)
 		{
-			Event& event=*(it->first);
-			Part* part=it->second;
+			const Event& event=*(it->first);
+			const Part* part=it->second;
 			
 			unsigned tick = event.tick() + part->tick();
 			float curr_val= (float)start_val  +  (float)(end_val-start_val) * (tick-from) / (to-from);
@@ -713,18 +713,18 @@ bool crescendo(const set<Part*>& parts, int range, int start_val, int end_val, b
 		return false;
 }
 
-bool move_notes(const set<Part*>& parts, int range, signed int ticks)
+bool move_notes(const set<const Part*>& parts, int range, signed int ticks)
 {
-	map<Event*, Part*> events = get_events(parts, range);
+	map<const Event*, const Part*> events = get_events(parts, range);
 	Undo operations;
-	map<Part*, int> partlen;
+	map<const Part*, int> partlen;
 	
 	if ( (!events.empty()) && (ticks!=0) )
 	{
-		for (map<Event*, Part*>::iterator it=events.begin(); it!=events.end(); it++)
+		for (map<const Event*, const Part*>::iterator it=events.begin(); it!=events.end(); it++)
 		{
-			Event& event=*(it->first);
-			Part* part=it->second;
+			const Event& event=*(it->first);
+			const Part* part=it->second;
 			bool del=false;
 
 			Event newEvent = event.clone();
@@ -752,7 +752,7 @@ bool move_notes(const set<Part*>& parts, int range, signed int ticks)
 				operations.push_back(UndoOp(UndoOp::DeleteEvent, event, part, false, false));
 		}
 		
-		for (map<Part*, int>::iterator it=partlen.begin(); it!=partlen.end(); it++)
+		for (map<const Part*, int>::iterator it=partlen.begin(); it!=partlen.end(); it++)
 			schedule_resize_all_same_len_clone_parts(it->first, it->second, operations);
 		
 		return MusEGlobal::song->applyOperationGroup(operations);
@@ -762,29 +762,29 @@ bool move_notes(const set<Part*>& parts, int range, signed int ticks)
 }
 
 
-bool delete_overlaps(const set<Part*>& parts, int range)
+bool delete_overlaps(const set<const Part*>& parts, int range)
 {
-	map<Event*, Part*> events = get_events(parts, range);
+	map<const Event*, const Part*> events = get_events(parts, range);
 	Undo operations;
 	
-	set<Event*> deleted_events;
+	set<const Event*> deleted_events;
 	
 	if (!events.empty())
 	{
-		for (map<Event*, Part*>::iterator it1=events.begin(); it1!=events.end(); it1++)
+		for (map<const Event*, const Part*>::iterator it1=events.begin(); it1!=events.end(); it1++)
 		{
-			Event& event1=*(it1->first);
-			Part* part1=it1->second;
+			const Event& event1=*(it1->first);
+			const Part* part1=it1->second;
 			
 			// we may NOT optimize by letting it2 start at (it1 +1); this optimisation
 			// is only allowed when events was sorted by time. it is, however, sorted
 			// randomly by pointer.
-			for (map<Event*, Part*>::iterator it2=events.begin(); it2!=events.end(); it2++)
+			for (map<const Event*, const Part*>::iterator it2=events.begin(); it2!=events.end(); it2++)
 			{
-				Event& event2=*(it2->first);
-				Part* part2=it2->second;
+				const Event& event2=*(it2->first);
+				const Part* part2=it2->second;
 				
-				if ( (part1->events()==part2->events()) && // part1 and part2 are the same or are duplicates
+				if ( (part1->isCloneOf(part2)) &&          // part1 and part2 are the same or are duplicates
 				     (&event1 != &event2) &&               // and event1 and event2 aren't the same
 				     (deleted_events.find(&event2) == deleted_events.end()) ) //and event2 hasn't been deleted before
 				{
@@ -817,34 +817,34 @@ bool delete_overlaps(const set<Part*>& parts, int range)
 		return false;
 }
 
-bool legato(const set<Part*>& parts, int range, int min_len, bool dont_shorten)
+bool legato(const set<const Part*>& parts, int range, int min_len, bool dont_shorten)
 {
-	map<Event*, Part*> events = get_events(parts, range);
+	map<const Event*, const Part*> events = get_events(parts, range);
 	Undo operations;
 	
 	if (min_len<=0) min_len=1;
 	
 	if (!events.empty())
 	{
-		for (map<Event*, Part*>::iterator it1=events.begin(); it1!=events.end(); it1++)
+		for (map<const Event*, const Part*>::iterator it1=events.begin(); it1!=events.end(); it1++)
 		{
-			Event& event1=*(it1->first);
-			Part* part1=it1->second;
+			const Event& event1=*(it1->first);
+			const Part* part1=it1->second;
 			
 			unsigned len=INT_MAX;
 			// we may NOT optimize by letting it2 start at (it1 +1); this optimisation
 			// is only allowed when events was sorted by time. it is, however, sorted
 			// randomly by pointer.
-			for (map<Event*, Part*>::iterator it2=events.begin(); it2!=events.end(); it2++)
+			for (map<const Event*, const Part*>::iterator it2=events.begin(); it2!=events.end(); it2++)
 			{
-				Event& event2=*(it2->first);
-				Part* part2=it2->second;
+				const Event& event2=*(it2->first);
+				const Part* part2=it2->second;
 				
 				bool relevant = (event2.tick() >= event1.tick() + min_len);
 				if (dont_shorten)
 					relevant = relevant && (event2.tick() >= event1.endTick());
 				
-				if ( (part1->events()==part2->events()) &&  // part1 and part2 are the same or are duplicates
+				if ( (part1->isCloneOf(part2)) &&           // part1 and part2 are the same or are duplicates
 				      relevant &&                           // they're not too near (respect min_len and dont_shorten)
 				     (event2.tick()-event1.tick() < len ) ) // that's the nearest relevant following note
 					len=event2.tick()-event1.tick();
@@ -869,7 +869,7 @@ bool legato(const set<Part*>& parts, int range, int min_len, bool dont_shorten)
 
 
 
-void copy_notes(const set<Part*>& parts, int range)
+void copy_notes(const set<const Part*>& parts, int range)
 {
 	QMimeData* drag = selected_events_to_mime(parts,range);
 
@@ -926,7 +926,7 @@ unsigned get_clipboard_len()
 	return get_groupedevents_len(s);
 }
 
-bool paste_notes(Part* paste_into_part)
+bool paste_notes(const Part* paste_into_part)
 {
 	unsigned temp_begin = AL::sigmap.raster1(MusEGlobal::song->cpos(),0);
 	unsigned temp_end = AL::sigmap.raster2(temp_begin + get_clipboard_len(), 0);
@@ -943,7 +943,7 @@ bool paste_notes(Part* paste_into_part)
 	return true;
 }
 
-void paste_notes(int max_distance, bool always_new_part, bool never_new_part, Part* paste_into_part, int amount, int raster)
+void paste_notes(int max_distance, bool always_new_part, bool never_new_part, const Part* paste_into_part, int amount, int raster)
 {
 	QString tmp="x-muse-groupedeventlists"; // QClipboard::text() expects a QString&, not a QString :(
 	QString s = QApplication::clipboard()->text(tmp, QClipboard::Clipboard);  // TODO CHECK Tim.
@@ -951,12 +951,12 @@ void paste_notes(int max_distance, bool always_new_part, bool never_new_part, Pa
 }
 
 // if nothing is selected/relevant, this function returns NULL
-QMimeData* selected_events_to_mime(const set<Part*>& parts, int range)
+QMimeData* selected_events_to_mime(const set<const Part*>& parts, int range)
 {
     unsigned start_tick = INT_MAX; //will be the tick of the first event or INT_MAX if no events are there
 
-    for (set<Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
-        for (iEvent ev=(*part)->events()->begin(); ev!=(*part)->events()->end(); ev++)
+    for (set<const Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
+        for (ciEvent ev=(*part)->events().begin(); ev!=(*part)->events().end(); ev++)
             if (is_relevant(ev->second, *part, range))
                 if (ev->second.tick() < start_tick)
                     start_tick=ev->second.tick();
@@ -978,10 +978,10 @@ QMimeData* selected_events_to_mime(const set<Part*>& parts, int range)
     Xml xml(tmp);
     int level = 0;
 
-    for (set<Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
+    for (set<const Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
     {
         xml.tag(level++, "eventlist part_id=\"%d\"", (*part)->sn());
-        for (iEvent ev=(*part)->events()->begin(); ev!=(*part)->events()->end(); ev++)
+        for (ciEvent ev=(*part)->events().begin(); ev!=(*part)->events().end(); ev++)
             if (is_relevant(ev->second, *part, range))
                 ev->second.write(level, xml, -start_tick);
         xml.etag(--level, "eventlist");
@@ -993,7 +993,7 @@ QMimeData* selected_events_to_mime(const set<Part*>& parts, int range)
 }
 
 // if nothing is selected/relevant, this function returns NULL
-QMimeData* parts_to_mime(const set<Part*>& parts)
+QMimeData* parts_to_mime(const set<const Part*>& parts)
 {
 	
 	//---------------------------------------------------
@@ -1012,7 +1012,7 @@ QMimeData* parts_to_mime(const set<Part*>& parts)
 	
     bool midi=false;
     bool wave=false;
-	for (set<Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
+	for (set<const Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
 	{
         if ((*part)->track()->type() == MusECore::Track::MIDI)
             midi=true;
@@ -1102,11 +1102,11 @@ bool read_eventlist_and_part(Xml& xml, EventList* el, int* part_id) // true on s
 	}
 }
 
-void paste_at(const QString& pt, int pos, int max_distance, bool always_new_part, bool never_new_part, Part* paste_into_part, int amount, int raster)
+void paste_at(const QString& pt, int pos, int max_distance, bool always_new_part, bool never_new_part, const Part* paste_into_part, int amount, int raster)
 {
 	Undo operations;
-	map<Part*, unsigned> expand_map;
-	map<Part*, set<Part*> > new_part_map;
+	map<const Part*, unsigned> expand_map;
+	map<const Part*, set<const Part*> > new_part_map;
 	
 	QByteArray pt_= pt.toLatin1();
 	Xml xml(pt_.constData());
@@ -1128,9 +1128,9 @@ void paste_at(const QString& pt, int pos, int max_distance, bool always_new_part
 		
 					if (read_eventlist_and_part(xml, &el, &part_id))
 					{
-						Part* dest_part;
+						const Part* dest_part;
 						Track* dest_track;
-						Part* old_dest_part;
+						const Part* old_dest_part;
 						
 						if (paste_into_part == NULL)
 							dest_part = partFromSerialNumber(part_id);
@@ -1157,13 +1157,12 @@ void paste_at(const QString& pt, int pos, int max_distance, bool always_new_part
 								
 								if (create_new_part)
 								{
-									dest_part = dest_track->newPart();
-									dest_part->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it
-																										// so we must decrement it first :/
-									dest_part->setTick(AL::sigmap.raster1(first_paste_tick, config.division));
+									Part* newpart = dest_track->newPart();
+									newpart->setTick(AL::sigmap.raster1(first_paste_tick, config.division));
 
 									new_part_map[old_dest_part].insert(dest_part);
 									operations.push_back(UndoOp(UndoOp::AddPart, dest_part));
+									dest_part = newpart;
 								}
 								
 								for (iEvent i = el.begin(); i != el.end(); ++i)
@@ -1218,7 +1217,7 @@ void paste_at(const QString& pt, int pos, int max_distance, bool always_new_part
 	
 	out_of_paste_at_for:
 	
-	for (map<Part*, unsigned>::iterator it = expand_map.begin(); it!=expand_map.end(); it++)
+	for (map<const Part*, unsigned>::iterator it = expand_map.begin(); it!=expand_map.end(); it++)
 		if (it->second != it->first->lenTick())
 			schedule_resize_all_same_len_clone_parts(it->first, it->second, operations);
 
@@ -1228,61 +1227,76 @@ void paste_at(const QString& pt, int pos, int max_distance, bool always_new_part
 	MusEGlobal::song->update(SC_SELECTION);
 }
 
-void select_all(const std::set<Part*>& parts)
+void select_all(const set<const Part*>& parts)
 {
-	for (set<Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
-		for (iEvent ev_it=(*part)->events()->begin(); ev_it!=(*part)->events()->end(); ev_it++)
+	Undo operations;
+	operations.combobreaker=true;
+	
+	for (set<const Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
+		for (ciEvent ev_it=(*part)->events().begin(); ev_it!=(*part)->events().end(); ev_it++)
 		{
-			Event& event=ev_it->second;
-			event.setSelected(true);
+			const Event& event=ev_it->second;
+			operations.push_back(UndoOp(UndoOp::SelectEvent,event, true, event.selected()));
 		}
-	MusEGlobal::song->update(SC_SELECTION);
+	MusEGlobal::song->applyOperationGroup(operations);
 }
 
-void select_none(const std::set<Part*>& parts)
+void select_none(const set<const Part*>& parts)
 {
-	for (set<Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
-		for (iEvent ev_it=(*part)->events()->begin(); ev_it!=(*part)->events()->end(); ev_it++)
+	Undo operations;
+	operations.combobreaker=true;
+	
+	for (set<const Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
+		for (ciEvent ev_it=(*part)->events().begin(); ev_it!=(*part)->events().end(); ev_it++)
 		{
-			Event& event=ev_it->second;
-			event.setSelected(false);
+			const Event& event=ev_it->second;
+			operations.push_back(UndoOp(UndoOp::SelectEvent,event, false, event.selected()));
 		}
-	MusEGlobal::song->update(SC_SELECTION);
+	MusEGlobal::song->applyOperationGroup(operations);
 }
 
-void select_invert(const std::set<Part*>& parts)
+void select_invert(const set<const Part*>& parts)
 {
-	for (set<Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
-		for (iEvent ev_it=(*part)->events()->begin(); ev_it!=(*part)->events()->end(); ev_it++)
+	Undo operations;
+	operations.combobreaker=true;
+	
+	for (set<const Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
+		for (ciEvent ev_it=(*part)->events().begin(); ev_it!=(*part)->events().end(); ev_it++)
 		{
-			Event& event=ev_it->second;
-			event.setSelected(!event.selected());
+			const Event& event=ev_it->second;
+			operations.push_back(UndoOp(UndoOp::SelectEvent,event, !event.selected(), event.selected()));
 		}
-	MusEGlobal::song->update(SC_SELECTION);
+	MusEGlobal::song->applyOperationGroup(operations);
 }
 
-void select_in_loop(const std::set<Part*>& parts)
+void select_in_loop(const set<const Part*>& parts)
 {
 	select_none(parts);
-	for (set<Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
-		for (iEvent ev_it=(*part)->events()->begin(); ev_it!=(*part)->events()->end(); ev_it++)
+	Undo operations;
+	operations.combobreaker=true;
+	
+	for (set<const Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
+		for (ciEvent ev_it=(*part)->events().begin(); ev_it!=(*part)->events().end(); ev_it++)
 		{
-			Event& event=ev_it->second;
-			event.setSelected((event.tick()>=MusEGlobal::song->lpos() && event.endTick()<=MusEGlobal::song->rpos()));
+			const Event& event=ev_it->second;
+			operations.push_back(UndoOp(UndoOp::SelectEvent,event, (event.tick()>=MusEGlobal::song->lpos() && event.endTick()<=MusEGlobal::song->rpos()), event.selected()));
 		}
-	MusEGlobal::song->update(SC_SELECTION);
+	MusEGlobal::song->applyOperationGroup(operations);
 }
 
-void select_not_in_loop(const std::set<Part*>& parts)
+void select_not_in_loop(const set<const Part*>& parts)
 {
 	select_none(parts);
-	for (set<Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
-		for (iEvent ev_it=(*part)->events()->begin(); ev_it!=(*part)->events()->end(); ev_it++)
+	Undo operations;
+	operations.combobreaker=true;
+	
+	for (set<const Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
+		for (ciEvent ev_it=(*part)->events().begin(); ev_it!=(*part)->events().end(); ev_it++)
 		{
-			Event& event=ev_it->second;
-			event.setSelected(!(event.tick()>=MusEGlobal::song->lpos() && event.endTick()<=MusEGlobal::song->rpos()));
+			const Event& event=ev_it->second;
+			operations.push_back(UndoOp(UndoOp::SelectEvent,event, !(event.tick()>=MusEGlobal::song->lpos() && event.endTick()<=MusEGlobal::song->rpos()), event.selected()));
 		}
-	MusEGlobal::song->update(SC_SELECTION);
+	MusEGlobal::song->applyOperationGroup(operations);
 }
 
 
@@ -1299,10 +1313,9 @@ void shrink_parts(int raster)
 		for (iPart part = (*track)->parts()->begin(); part != (*track)->parts()->end(); part++)
 			if (part->second->selected())
 			{
-				EventList* events=part->second->events();
 				unsigned len=0;
 				
-				for (iEvent ev=events->begin(); ev!=events->end(); ev++)
+				for (ciEvent ev=part->second->events().begin(); ev!=part->second->events().end(); ev++)
 					if (ev->second.endTick() > len)
 						len=ev->second.endTick();
 				
@@ -1310,46 +1323,36 @@ void shrink_parts(int raster)
 				if (len<min_len) len=min_len;
 				
 				if (len < part->second->lenTick())
-				{
-					MidiPart* new_part = new MidiPart(*(MidiPart*)part->second);
-					new_part->setLenTick(len);
-					operations.push_back(UndoOp(UndoOp::ModifyPart, part->second, new_part, true, false));
-				}
+					operations.push_back(UndoOp(UndoOp::ModifyPartLength, part->second, part->second->lenTick(), len, true, false));
 			}
 	
 	MusEGlobal::song->applyOperationGroup(operations);
 }
 
 
-void schedule_resize_all_same_len_clone_parts(Part* part, unsigned new_len, Undo& operations)
+void schedule_resize_all_same_len_clone_parts(const Part* part, unsigned new_len, Undo& operations)
 {
 	QSet<const Part*> already_done;
 	
 	for (Undo::iterator op_it=operations.begin(); op_it!=operations.end();op_it++)
-		if (op_it->type==UndoOp::ModifyPart || op_it->type==UndoOp::DeletePart)
-			already_done.insert(op_it->nPart);
+		if (op_it->type==UndoOp::DeletePart)
+			already_done.insert(op_it->part);
 			
 	unsigned old_len= part->type() == Pos::FRAMES ? part->lenFrame() : part->lenTick();
 	if (old_len!=new_len)
 	{
-		Part* part_it=part;
+		const Part* part_it=part;
 		do
 		{
 			if (part->type() == Pos::FRAMES)
 			{
 			  if (part_it->lenFrame()==old_len && !already_done.contains(part_it))
-			  {
-				  WavePart* new_part = new WavePart(*(WavePart*)part_it);
-				  new_part->setLenFrame(new_len);
-				  operations.push_back(UndoOp(UndoOp::ModifyPart, part_it, new_part, true, false));
-			  }
+				  operations.push_back(UndoOp(UndoOp::ModifyPartLengthFrames, part_it, part_it->lenFrame(), new_len, true, false)); // FIXME FINDMICH frames suck :(
 			}
 			else
 			if (part_it->lenTick()==old_len && !already_done.contains(part_it))
 			{
-				MidiPart* new_part = new MidiPart(*(MidiPart*)part_it);
-				new_part->setLenTick(new_len);
-				operations.push_back(UndoOp(UndoOp::ModifyPart, part_it, new_part, true, false));
+				operations.push_back(UndoOp(UndoOp::ModifyPartLength, part_it, part_it->lenTick(), new_len, true, false));
 			}
 			
 			part_it=part_it->nextClone();
@@ -1370,10 +1373,9 @@ void expand_parts(int raster)
 		for (iPart part = (*track)->parts()->begin(); part != (*track)->parts()->end(); part++)
 			if (part->second->selected())
 			{
-				EventList* events=part->second->events();
 				unsigned len=part->second->lenTick();
 				
-				for (iEvent ev=events->begin(); ev!=events->end(); ev++)
+				for (ciEvent ev=part->second->events().begin(); ev!=part->second->events().end(); ev++)
 					if (ev->second.endTick() > len)
 						len=ev->second.endTick();
 
@@ -1381,11 +1383,7 @@ void expand_parts(int raster)
 				if (len<min_len) len=min_len;
 								
 				if (len > part->second->lenTick())
-				{
-					MidiPart* new_part = new MidiPart(*(MidiPart*)part->second);
-					new_part->setLenTick(len);
-					operations.push_back(UndoOp(UndoOp::ModifyPart, part->second, new_part, true, false));
-				}
+					operations.push_back(UndoOp(UndoOp::ModifyPartLength, part->second, part->second->lenTick(), len, true, false));
 			}
 			
 	MusEGlobal::song->applyOperationGroup(operations);
@@ -1394,7 +1392,7 @@ void expand_parts(int raster)
 void clean_parts()
 {
 	Undo operations;
-	set<Part*> already_processed;
+	set<const Part*> already_processed;
 	
 	TrackList* tracks = MusEGlobal::song->tracks();
 	for (iTrack track = tracks->begin(); track != tracks->end(); track++)
@@ -1406,7 +1404,7 @@ void clean_parts()
 				// multiple clones)
 				unsigned len=0;
 				
-				Part* part_it=part->second;
+				const Part* part_it=part->second;
 				do
 				{
 					if (part_it->lenTick() > len)
@@ -1419,8 +1417,7 @@ void clean_parts()
 				
 				// erase all events exceeding the longest clone of this part
 				// (i.e., erase all hidden events) or shorten them
-				EventList* el = part->second->events();
-				for (iEvent ev=el->begin(); ev!=el->end(); ev++)
+				for (ciEvent ev=part->second->events().begin(); ev!=part->second->events().end(); ev++)
 					if (ev->second.tick() >= len)
 						operations.push_back(UndoOp(UndoOp::DeleteEvent, ev->second, part->second, true, true));
 					else if (ev->second.endTick() > len)
@@ -1435,33 +1432,67 @@ void clean_parts()
 	MusEGlobal::song->applyOperationGroup(operations);
 }
 
+
+bool merge_with_next_part(const Part* oPart)
+{
+	const Track* track = oPart->track();
+	
+	if(track->type() != Track::WAVE && !track->isMidiTrack())
+		return false;
+	
+	const PartList* pl   = track->cparts();
+	const Part* nextPart = 0;
+
+	for (ciPart ip = pl->begin(); ip != pl->end(); ++ip)
+	{
+			if (ip->second == oPart)
+			{
+				++ip;
+				if (ip == pl->end())
+						return false;
+				nextPart = ip->second;
+				break;
+				}
+			}
+	
+	if (nextPart)
+	{
+		set<const Part*> parts;
+		parts.insert(oPart);
+		parts.insert(nextPart);
+		return merge_parts(parts);
+	}
+	else
+		return false;
+}
+
 bool merge_selected_parts()
 {
-	set<Part*> temp = get_all_selected_parts();
+	set<const Part*> temp = get_all_selected_parts();
 	return merge_parts(temp);
 }
 
-bool merge_parts(const set<Part*>& parts)
+bool merge_parts(const set<const Part*>& parts)
 {
-	set<Track*> tracks;
-	for (set<Part*>::iterator it=parts.begin(); it!=parts.end(); it++)
+	set<const Track*> tracks;
+	for (set<const Part*>::iterator it=parts.begin(); it!=parts.end(); it++)
 		tracks.insert( (*it)->track() );
 
 	Undo operations;
 	
 	// process tracks separately
-	for (set<Track*>::iterator t_it=tracks.begin(); t_it!=tracks.end(); t_it++)
+	for (set<const Track*>::iterator t_it=tracks.begin(); t_it!=tracks.end(); t_it++)
 	{
-		Track* track=*t_it;
+		const Track* track=*t_it;
 
 		unsigned begin=INT_MAX, end=0;
-		Part* first_part=NULL;
+		const Part* first_part=NULL;
 		
 		// find begin of the first and end of the last part
-		for (set<Part*>::iterator it=parts.begin(); it!=parts.end(); it++)
+		for (set<const Part*>::iterator it=parts.begin(); it!=parts.end(); it++)
 			if ((*it)->track()==track)
 			{
-				Part* p=*it;
+				const Part* p=*it;
 				if (p->tick() < begin)
 				{
 					begin=p->tick();
@@ -1479,30 +1510,25 @@ bool merge_parts(const set<Part*>& parts)
 		}
 		
 		// create and prepare the new part
-		Part* new_part = track->newPart(first_part); 
+		Part* new_part = first_part->duplicateEmpty();
 		new_part->setTick(begin);
 		new_part->setLenTick(end-begin);
 		
-		EventList* new_el = new_part->events();
-		new_el->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it
-		                     // so we must decrement it first :/
-		new_el->clear();
-		
 		// copy all events from the source parts into the new part
-		for (set<Part*>::iterator p_it=parts.begin(); p_it!=parts.end(); p_it++)
+		for (set<const Part*>::iterator p_it=parts.begin(); p_it!=parts.end(); p_it++)
 			if ((*p_it)->track()==track)
 			{
-				EventList* old_el= (*p_it)->events();
-				for (iEvent ev_it=old_el->begin(); ev_it!=old_el->end(); ev_it++)
+				const EventList& old_el= (*p_it)->events();
+				for (ciEvent ev_it=old_el.begin(); ev_it!=old_el.end(); ev_it++)
 				{
-					Event new_event=ev_it->second;
+					Event new_event=ev_it->second.clone();
 					new_event.setTick( new_event.tick() + (*p_it)->tick() - new_part->tick() );
-					new_el->add(new_event);
+					new_part->nonconst_events().add(new_event);
 				}
 			}
 		
 		// delete all the source parts
-		for (set<Part*>::iterator it=parts.begin(); it!=parts.end(); it++)
+		for (set<const Part*>::iterator it=parts.begin(); it!=parts.end(); it++)
 			if ((*it)->track()==track)
 				operations.push_back( UndoOp(UndoOp::DeletePart, *it) );
 		// and add the new one
@@ -1512,4 +1538,49 @@ bool merge_parts(const set<Part*>& parts)
 	return MusEGlobal::song->applyOperationGroup(operations);
 }
 
+bool split_part(const Part* part, int tick)
+{
+	int l1 = tick - part->tick();
+	int l2 = part->lenTick() - l1;
+	if (l1 <= 0 || l2 <= 0)
+			return false;
+	Part* p1;
+	Part* p2;
+	part->splitPart(tick, p1, p2);
+	
+	MusEGlobal::song->informAboutNewParts(part, p1);
+	MusEGlobal::song->informAboutNewParts(part, p2);
+
+	Undo operations;
+	operations.push_back(UndoOp(UndoOp::DeletePart, part));
+	operations.push_back(UndoOp(UndoOp::AddPart, p1));
+	operations.push_back(UndoOp(UndoOp::AddPart, p2));
+	return MusEGlobal::song->applyOperationGroup(operations);
+}
+
+bool delete_selected_parts()
+{
+	Undo operations;
+	bool partSelected = false;
+
+	TrackList* tl = MusEGlobal::song->tracks();
+
+	for (iTrack it = tl->begin(); it != tl->end(); ++it)
+	{
+		PartList* pl = (*it)->parts();
+		for (iPart ip = pl->begin(); ip != pl->end(); ++ip)
+		{
+				if (ip->second->selected())
+				{
+					operations.push_back(UndoOp(UndoOp::DeletePart,ip->second));
+					partSelected = true;
+					}
+				}
+		}
+	
+	MusEGlobal::song->applyOperationGroup(operations);
+	
+	return partSelected;
+}
+
 } // namespace MusECore
diff --git a/muse2/muse/functions.h b/muse2/muse/functions.h
index 31c91fe4..28e178da 100644
--- a/muse2/muse/functions.h
+++ b/muse2/muse/functions.h
@@ -39,36 +39,36 @@ class QMimeData;
 namespace MusECore {
 class Undo;
 
-std::set<Part*> partlist_to_set(PartList* pl);
-std::set<Part*> part_to_set(Part* p);
-std::map<Event*, Part*> get_events(const std::set<Part*>& parts, int range);
+std::set<const Part*> partlist_to_set(PartList* pl);
+std::set<const Part*> part_to_set(const Part* p);
+std::map<const Event*, const Part*> get_events(const std::set<const Part*>& parts, int range);
 
 //these functions simply do their job, non-interactively
-bool modify_velocity(const std::set<Part*>& parts, int range, int rate, int offset=0);
-bool modify_off_velocity(const std::set<Part*>& parts, int range, int rate, int offset=0);
-bool modify_notelen(const std::set<Part*>& parts, int range, int rate, int offset=0);
-bool quantize_notes(const std::set<Part*>& parts, int range, int raster, bool len=false, int strength=100, int swing=0, int threshold=0);
-bool erase_notes(const std::set<Part*>& parts, int range, int velo_threshold=0, bool velo_thres_used=false, int len_threshold=0, bool len_thres_used=false);
-bool delete_overlaps(const std::set<Part*>& parts, int range);
-bool set_notelen(const std::set<Part*>& parts, int range, int len);
-bool move_notes(const std::set<Part*>& parts, int range, signed int ticks);
-bool transpose_notes(const std::set<Part*>& parts, int range, signed int halftonesteps);
-bool crescendo(const std::set<Part*>& parts, int range, int start_val, int end_val, bool absolute);
-bool legato(const std::set<Part*>& parts, int range, int min_len=1, bool dont_shorten=false);
+bool modify_velocity(const std::set<const Part*>& parts, int range, int rate, int offset=0);
+bool modify_off_velocity(const std::set<const Part*>& parts, int range, int rate, int offset=0);
+bool modify_notelen(const std::set<const Part*>& parts, int range, int rate, int offset=0);
+bool quantize_notes(const std::set<const Part*>& parts, int range, int raster, bool len=false, int strength=100, int swing=0, int threshold=0);
+bool erase_notes(const std::set<const Part*>& parts, int range, int velo_threshold=0, bool velo_thres_used=false, int len_threshold=0, bool len_thres_used=false);
+bool delete_overlaps(const std::set<const Part*>& parts, int range);
+bool set_notelen(const std::set<const Part*>& parts, int range, int len);
+bool move_notes(const std::set<const Part*>& parts, int range, signed int ticks);
+bool transpose_notes(const std::set<const Part*>& parts, int range, signed int halftonesteps);
+bool crescendo(const std::set<const Part*>& parts, int range, int start_val, int end_val, bool absolute);
+bool legato(const std::set<const Part*>& parts, int range, int min_len=1, bool dont_shorten=false);
 
 
 //the below functions automatically open the dialog
 //they return true if you click "ok" and false if "abort"
-bool modify_velocity(const std::set<Part*>& parts);
-bool modify_notelen(const std::set<Part*>& parts);
-bool quantize_notes(const std::set<Part*>& parts);
-bool set_notelen(const std::set<Part*>& parts);
-bool move_notes(const std::set<Part*>& parts);
-bool transpose_notes(const std::set<Part*>& parts);
-bool crescendo(const std::set<Part*>& parts);
-bool erase_notes(const std::set<Part*>& parts);
-bool delete_overlaps(const std::set<Part*>& parts);
-bool legato(const std::set<Part*>& parts);
+bool modify_velocity(const std::set<const Part*>& parts);
+bool modify_notelen(const std::set<const Part*>& parts);
+bool quantize_notes(const std::set<const Part*>& parts);
+bool set_notelen(const std::set<const Part*>& parts);
+bool move_notes(const std::set<const Part*>& parts);
+bool transpose_notes(const std::set<const Part*>& parts);
+bool crescendo(const std::set<const Part*>& parts);
+bool erase_notes(const std::set<const Part*>& parts);
+bool delete_overlaps(const std::set<const Part*>& parts);
+bool legato(const std::set<const Part*>& parts);
 
 //the below functions operate on selected parts
 bool modify_velocity();
@@ -84,29 +84,32 @@ bool legato();
 
 
 //functions for copy'n'paste
-void copy_notes(const std::set<Part*>& parts, int range);
-bool paste_notes(Part* paste_into_part=NULL); // shows a dialog
-void paste_notes(int max_distance=3072, bool always_new_part=false, bool never_new_part=false, Part* paste_into_part=NULL, int amount=1, int raster=3072);
-QMimeData* selected_events_to_mime(const std::set<Part*>& parts, int range);
-QMimeData* parts_to_mime(const std::set<Part*>& parts);
+void copy_notes(const std::set<const Part*>& parts, int range);
+bool paste_notes(const Part* paste_into_part=NULL); // shows a dialog
+void paste_notes(int max_distance=3072, bool always_new_part=false, bool never_new_part=false, const Part* paste_into_part=NULL, int amount=1, int raster=3072);
+QMimeData* selected_events_to_mime(const std::set<const Part*>& parts, int range);
+QMimeData* parts_to_mime(const std::set<const Part*>& parts);
 
 
-void paste_at(const QString& pt, int pos, int max_distance=3072, bool always_new_part=false, bool never_new_part=false, Part* paste_into_part=NULL, int amount=1, int raster=3072);
+void paste_at(const QString& pt, int pos, int max_distance=3072, bool always_new_part=false, bool never_new_part=false, const Part* paste_into_part=NULL, int amount=1, int raster=3072);
 
 //functions for selections
-void select_all(const std::set<Part*>& parts);
-void select_none(const std::set<Part*>& parts);
-void select_invert(const std::set<Part*>& parts);
-void select_in_loop(const std::set<Part*>& parts);
-void select_not_in_loop(const std::set<Part*>& parts);
+void select_all(const std::set<const Part*>& parts);
+void select_none(const std::set<const Part*>& parts);
+void select_invert(const std::set<const Part*>& parts);
+void select_in_loop(const std::set<const Part*>& parts);
+void select_not_in_loop(const std::set<const Part*>& parts);
 
 //functions for parts
 void shrink_parts(int raster=-1); //negative values mean "config.division"
 void expand_parts(int raster=-1);
-void schedule_resize_all_same_len_clone_parts(Part* part, unsigned new_len, Undo& operations);
+void schedule_resize_all_same_len_clone_parts(const Part* part, unsigned new_len, Undo& operations);
 void clean_parts();
+bool merge_with_next_part(const Part* part);
 bool merge_selected_parts();
-bool merge_parts(const std::set<Part*>& parts);
+bool merge_parts(const std::set<const Part*>& parts);
+bool split_part(const Part* part, int tick);
+bool delete_selected_parts();
 
 // internal
 QMimeData* file_to_mimedata(FILE *datafile, QString mimeType);
diff --git a/muse2/muse/helper.cpp b/muse2/muse/helper.cpp
index efb4ec68..75cbce9f 100644
--- a/muse2/muse/helper.cpp
+++ b/muse2/muse/helper.cpp
@@ -108,7 +108,7 @@ Part* partFromSerialNumber(int serial)
 	return NULL;
 }
 
-bool any_event_selected(const set<Part*>& parts, bool in_range)
+bool any_event_selected(const set<const Part*>& parts, bool in_range)
 {
   return !get_events(parts, in_range ? 3 : 1).empty();
 }
@@ -941,9 +941,9 @@ int populateMidiCtrlMenu(PopupMenu* menu, MusECore::PartList* part_list, MusECor
             if (i == sList.end()) {
                   bool used = false;
                   for (MusECore::iPart ip = part_list->begin(); ip != part_list->end(); ++ip) {
-                        MusECore::EventList* el = ip->second->events();
-                        for (MusECore::iEvent ie = el->begin(); ie != el->end(); ++ie) {
-                              MusECore::Event e = ie->second;
+                        const MusECore::EventList& el = ip->second->events();
+                        for (MusECore::ciEvent ie = el.begin(); ie != el.end(); ++ie) {
+                              const MusECore::Event& e = ie->second;
                               if(e.type() != MusECore::Controller)
                                 continue;
                               int ctl_num = e.dataA();
diff --git a/muse2/muse/helper.h b/muse2/muse/helper.h
index 33b2e9a0..b5763a4e 100644
--- a/muse2/muse/helper.h
+++ b/muse2/muse/helper.h
@@ -43,7 +43,7 @@ class PartList;
 
 QString pitch2string(int v);
 Part* partFromSerialNumber(int serial);
-bool any_event_selected(const std::set<Part*>&, bool in_range=false);
+bool any_event_selected(const std::set<const Part*>&, bool in_range=false);
 
 bool drummaps_almost_equal(const DrumMap* one, const DrumMap* two, int drummap_size=128);
 
diff --git a/muse2/muse/importmidi.cpp b/muse2/muse/importmidi.cpp
index e22d865e..b0affa24 100644
--- a/muse2/muse/importmidi.cpp
+++ b/muse2/muse/importmidi.cpp
@@ -249,8 +249,8 @@ bool MusE::importMidi(const QString name, bool merge)
       //    - calculate tick value for internal resolution
       //
       for (MusECore::iMidiFileTrack t = etl->begin(); t != etl->end(); ++t) {
-            MusECore::MPEventList* el  = &((*t)->events);
-            if (el->empty())
+            MusECore::MPEventList& el  = ((*t)->events);
+            if (el.empty())
                   continue;
             //
             // if we split the track, SYSEX and META events go into
@@ -264,7 +264,7 @@ bool MusE::importMidi(const QString name, bool merge)
             
             MusECore::iMPEvent ev;
             set< pair<int,int> > already_processed;
-            for (ev = el->begin(); ev != el->end(); ++ev)
+            for (ev = el.begin(); ev != el.end(); ++ev)
             {
               if (ev->type() != MusECore::ME_SYSEX && ev->type() != MusECore::ME_META)
               {
@@ -288,9 +288,7 @@ bool MusE::importMidi(const QString name, bool merge)
                         track->setOutPort(port);
 
                         MusECore::MidiPort* mport = &MusEGlobal::midiPorts[port];
-                        //MusECore::MidiInstrument* instr = mport->instrument();
-                        MusECore::EventList* mel = track->events();
-                        buildMidiEventList(mel, el, track, division, first, false); // Don't do loops.
+                        buildMidiEventList(&track->events, el, track, division, first, false); // Don't do loops.
                         first = false;
 
                         // Comment Added by T356.
@@ -305,8 +303,7 @@ bool MusE::importMidi(const QString name, bool merge)
                            {
                               track->setType(MusECore::Track::DRUM);
                               // remap drum pitch with drumOutmap (was: Inmap. flo93 thought this was wrong)
-                              MusECore::EventList* tevents = track->events();
-                              for (MusECore::iEvent i = tevents->begin(); i != tevents->end(); ++i) {
+                              for (MusECore::iEvent i = track->events.begin(); i != track->events.end(); ++i) {
                                     MusECore::Event ev  = i->second;
                                     if (ev.isNote()) {
                                           int pitch = MusEGlobal::drumOutmap[ev.pitch()];
@@ -339,8 +336,7 @@ bool MusE::importMidi(const QString name, bool merge)
                   MusECore::MidiTrack* track = new MusECore::MidiTrack();
                   track->setOutChannel(0);
                   track->setOutPort(0);
-                  MusECore::EventList* mel = track->events();
-                  buildMidiEventList(mel, el, track, division, true, false); // Do SysexMeta. Don't do loops.
+                  buildMidiEventList(&track->events, el, track, division, true, false); // Do SysexMeta. Don't do loops.
                   processTrack(track);
                   MusEGlobal::song->insertTrack0(track, -1);
                   }
@@ -383,8 +379,8 @@ bool MusE::importMidi(const QString name, bool merge)
 
 void MusE::processTrack(MusECore::MidiTrack* track)
       {
-      MusECore::EventList* tevents = track->events();
-      if (tevents->empty())
+      MusECore::EventList& tevents = track->events;
+      if (tevents.empty())
             return;
 
       //---------------------------------------------------
@@ -398,8 +394,8 @@ void MusE::processTrack(MusECore::MidiTrack* track)
       MusECore::PartList* pl = track->parts();
 
       int lastTick = 0;
-      for (MusECore::iEvent i = tevents->begin(); i != tevents->end(); ++i) {
-            MusECore::Event event = i->second;
+      for (MusECore::ciEvent i = tevents.begin(); i != tevents.end(); ++i) {
+            const MusECore::Event& event = i->second;
             int epos = event.tick() + event.lenTick();
             if (epos > lastTick)
                   lastTick = epos;
@@ -426,8 +422,8 @@ void MusE::processTrack(MusECore::MidiTrack* track)
               if (lastOff > x2) {        
                     continue;
                     }
-              MusECore::iEvent i1 = tevents->lower_bound(x1);
-              MusECore::iEvent i2 = tevents->lower_bound(x2);
+              MusECore::iEvent i1 = tevents.lower_bound(x1);
+              MusECore::iEvent i2 = tevents.lower_bound(x2);
   
               if (i1 == i2) {   // empty?
                     if (st != -1) {
@@ -444,8 +440,8 @@ void MusE::processTrack(MusECore::MidiTrack* track)
                           st = x1;    // begin new  part
                     //HACK:
                     //lastOff:
-                    for (MusECore::iEvent i = i1; i != i2; ++i) {
-                          MusECore::Event event = i->second;
+                    for (MusECore::ciEvent i = i1; i != i2; ++i) {
+                          const MusECore::Event& event = i->second;
                           if (event.type() == MusECore::Note) {
                                 int off = event.tick() + event.lenTick();
                                 if (off > lastOff)
@@ -480,28 +476,27 @@ void MusE::processTrack(MusECore::MidiTrack* track)
             MusECore::MidiPart* part = (MusECore::MidiPart*)(p->second);
             int stick = part->tick();
             int etick = part->tick() + part->lenTick();
-            MusECore::iEvent r1 = tevents->lower_bound(stick);
-            MusECore::iEvent r2 = tevents->lower_bound(etick);
+            MusECore::iEvent r1 = tevents.lower_bound(stick);
+            MusECore::iEvent r2 = tevents.lower_bound(etick);
             int startTick = part->tick();
 
-            MusECore::EventList* el = part->events();
             for (MusECore::iEvent i = r1; i != r2; ++i) {
-                  MusECore::Event ev = i->second;
+                  MusECore::Event& ev = i->second;
                   int ntick = ev.tick() - startTick;
                   ev.setTick(ntick);
-                  el->add(ev);
+                  part->nonconst_events().add(ev);
                   }
-            tevents->erase(r1, r2);
+            tevents.erase(r1, r2);
             }
 
-      if (tevents->size())
-            printf("-----------events left: %zd\n", tevents->size());
-      for (MusECore::iEvent i = tevents->begin(); i != tevents->end(); ++i) {
+      if (tevents.size())
+            printf("-----------events left: %zd\n", tevents.size());
+      for (MusECore::ciEvent i = tevents.begin(); i != tevents.end(); ++i) {
             printf("%d===\n", i->first);
             i->second.dump();
             }
       // all events should be processed:
-      if (!tevents->empty())
+      if (!tevents.empty())
         printf("THIS SHOULD NEVER HAPPEN: not all events processed at the end of MusE::processTrack()!\n");
       }
 
@@ -620,7 +615,7 @@ void MusE::importPartToTrack(QString& filename, unsigned tick, MusECore::Track*
                   if (tag == "part") {
                         // Read the part.
                         MusECore::Part* p = 0;
-                        p = readXmlPart(xml, track);
+                        p = MusECore::Part::readFromXml(xml, track);
                         // If it could not be created...
                         if(!p)
                         {
diff --git a/muse2/muse/liste/listedit.cpp b/muse2/muse/liste/listedit.cpp
index e1a49842..730ab5d8 100644
--- a/muse2/muse/liste/listedit.cpp
+++ b/muse2/muse/liste/listedit.cpp
@@ -247,8 +247,8 @@ void ListEdit::songChanged(MusECore::SongChangedFlags_t type)
                         MusECore::MidiPart* part = (MusECore::MidiPart*) (p->second);
                         if (part->sn() == curPartId)
                               curPart  = part;
-                        MusECore::EventList* el = part->events();
-                        for (MusECore::iEvent i = el->begin(); i != el->end(); ++i) {
+                        
+                        for (MusECore::ciEvent i = part->events().begin(); i != part->events().end(); ++i) {
                               EventListItem* item = new EventListItem(liste, i->second, part);
                               for (int col = 0; col < liste->columnCount(); ++col)
                                     item->setText(col, item->text(col));
diff --git a/muse2/muse/midi.cpp b/muse2/muse/midi.cpp
index 524329b1..d70b132c 100644
--- a/muse2/muse/midi.cpp
+++ b/muse2/muse/midi.cpp
@@ -198,7 +198,7 @@ QString nameSysex(unsigned int len, const unsigned char* buf)
 //      generally: how to handle incomplete messages
 //---------------------------------------------------------
 
-void buildMidiEventList(EventList* del, const MPEventList* el, MidiTrack* track,
+void buildMidiEventList(EventList* del, const MPEventList& el, MidiTrack* track,
    int div, bool addSysexMeta, bool doLoops)
       {
       int hbank    = 0xff;
@@ -211,7 +211,7 @@ void buildMidiEventList(EventList* del, const MPEventList* el, MidiTrack* track,
 
       EventList mel;
 
-      for (iMPEvent i = el->begin(); i != el->end(); ++i) {
+      for (iMPEvent i = el.begin(); i != el.end(); ++i) {
             MidiPlayEvent ev = *i;
             if (!addSysexMeta && (ev.type() == ME_SYSEX || ev.type() == ME_META))
                   continue;
@@ -305,7 +305,7 @@ void buildMidiEventList(EventList* del, const MPEventList* el, MidiTrack* track,
                                     iMPEvent ii = i;
                                     ++ii;
                                     bool found = false;
-                                    for (; ii != el->end(); ++ii) {
+                                    for (; ii != el.end(); ++ii) {
                                           MidiPlayEvent ev = *ii;
                                           if (ev.type() == ME_CONTROLLER) {
                                                 if (ev.dataA() == CTRL_LDATA) {
@@ -471,7 +471,7 @@ void buildMidiEventList(EventList* del, const MPEventList* el, MidiTrack* track,
                   e.setTick(tick);
                   mel.add(e);
                   }
-            }  // i != el->end()
+            }  // i != el.end()
 
 
       //---------------------------------------------------
@@ -625,7 +625,7 @@ void Audio::collectEvents(MusECore::MidiTrack* track, unsigned int cts, unsigned
             // dont play muted parts
             if (part->mute())
                   continue;
-            EventList* events = part->events();
+            const EventList& events = part->events();
             unsigned partTick = part->tick();
             unsigned partLen  = part->lenTick();
             int delay         = track->delay;
@@ -644,8 +644,8 @@ void Audio::collectEvents(MusECore::MidiTrack* track, unsigned int cts, unsigned
             if(etick > partLen)
               continue;
               
-            iEvent ie   = events->lower_bound(stick);
-            iEvent iend = events->lower_bound(etick);
+            ciEvent ie   = events.lower_bound(stick);
+            ciEvent iend = events.lower_bound(etick);
 
             for (; ie != iend; ++ie) {
                   Event ev = ie->second;
@@ -1009,7 +1009,6 @@ void Audio::processMidi()
             //
             if (track->recordFlag()) 
             {
-                  MusECore::MPEventList* rl = track->mpevents();
                   MusECore::MidiPort* tport = &MusEGlobal::midiPorts[port];
                   RouteList* irl = track->inRoutes();
                   for(ciRoute r = irl->begin(); r != irl->end(); ++r)
@@ -1063,7 +1062,7 @@ void Audio::processMidi()
                                 event.setTime(MusEGlobal::tempomap.frame2tick(event.time()));
                                 
                               if(recording) 
-                                rl->add(event);
+                                track->mpevents.add(event);
                             }      
                             dev->setSysexFIFOProcessed(true);
                           }
@@ -1252,7 +1251,7 @@ void Audio::processMidi()
                                             drumRecEvent.setB(preVelo);
                                             drumRecEvent.setPort(port); //rec-event to current port
                                             drumRecEvent.setChannel(track->outChannel()); //rec-event to current channel
-                                            rl->add(drumRecEvent);
+                                            track->mpevents.add(drumRecEvent);
                                         }
                                         else
                                         {
@@ -1263,7 +1262,7 @@ void Audio::processMidi()
                                             //  different port. That must have been wrong - buildMidiEventList would ignore that. Tim.
                                             drumRecEvent.setPort(port);  //rec-event to current port
                                             drumRecEvent.setChannel(track->outChannel()); //rec-event to current channel
-                                            rl->add(drumRecEvent);
+                                            track->mpevents.add(drumRecEvent);
                                         }    
                                       }
                                       else 
@@ -1277,7 +1276,7 @@ void Audio::processMidi()
                                             recEvent.setPort(port);
                                             recEvent.setChannel(track->outChannel());
                                                   
-                                            rl->add(recEvent);
+                                            track->mpevents.add(recEvent);
                                       }
                                 }
                             }
diff --git a/muse2/muse/midi.h b/muse2/muse/midi.h
index 86b11c97..c0f6e07f 100644
--- a/muse2/muse/midi.h
+++ b/muse2/muse/midi.h
@@ -126,7 +126,7 @@ QString midiMetaName(int);
 
 class MPEventList;
 class MidiTrack;
-extern void buildMidiEventList(EventList* mel, const MPEventList* el, MidiTrack* track, int division, bool addSysexMeta, bool doLoops);
+extern void buildMidiEventList(EventList* mel, const MPEventList& el, MidiTrack* track, int division, bool addSysexMeta, bool doLoops);
 
 } // namespace MusECore
 
diff --git a/muse2/muse/midiedit/dcanvas.cpp b/muse2/muse/midiedit/dcanvas.cpp
index ebe3a6c8..ba18d8a3 100644
--- a/muse2/muse/midiedit/dcanvas.cpp
+++ b/muse2/muse/midiedit/dcanvas.cpp
@@ -80,7 +80,7 @@ DEvent::DEvent(MusECore::Event e, MusECore::Part* p, int instr)
 //   addItem
 //---------------------------------------------------------
 
-CItem* DrumCanvas::addItem(MusECore::Part* part, MusECore::Event& event)
+CItem* DrumCanvas::addItem(MusECore::Part* part, const MusECore::Event& event)
       {
       if (signed(event.tick())<0) {
             printf("ERROR: trying to add event before current part!\n");
@@ -516,11 +516,10 @@ void DrumCanvas::newItem(CItem* item, bool noSnap, bool replace)
     event.setPitch(npitch);
     // check for existing event
     //    if found change command semantic from insert to delete
-    MusECore::EventList* el = part->events();
-    MusECore::iEvent lower  = el->lower_bound(event.tick());
-    MusECore::iEvent upper  = el->upper_bound(event.tick());
+    MusECore::ciEvent lower  = part->events().lower_bound(event.tick());
+    MusECore::ciEvent upper  = part->events().upper_bound(event.tick());
 
-    for (MusECore::iEvent i = lower; i != upper; ++i) {
+    for (MusECore::ciEvent i = lower; i != upper; ++i) {
           MusECore::Event ev = i->second;
           if(!ev.isNote())
             continue;
@@ -1027,10 +1026,10 @@ void DrumCanvas::mapChanged(int spitch, int dpitch)
    if (old_style_drummap_mode)
    {
       MusECore::Undo operations;
-      std::vector< std::pair<MusECore::Part*, MusECore::Event*> > delete_events;
+      std::vector< std::pair<MusECore::Part*, MusECore::Event> > delete_events;
       std::vector< std::pair<MusECore::Part*, MusECore::Event> > add_events;
       
-      typedef std::vector< std::pair<MusECore::Part*, MusECore::Event*> >::iterator idel_ev;
+      typedef std::vector< std::pair<MusECore::Part*, MusECore::Event> >::iterator idel_ev;
       typedef std::vector< std::pair<MusECore::Part*, MusECore::Event> >::iterator iadd_ev;
       
       MusECore::MidiTrackList* tracks = MusEGlobal::song->midis();
@@ -1042,9 +1041,9 @@ void DrumCanvas::mapChanged(int spitch, int dpitch)
             MusECore::MidiPort* mp = &MusEGlobal::midiPorts[curTrack->outPort()];
             MusECore::PartList* parts= curTrack->parts();
             for (MusECore::iPart part = parts->begin(); part != parts->end(); ++part) {
-                  MusECore::EventList* events = part->second->events();
+                  const MusECore::EventList& events = part->second->events();
                   MusECore::Part* thePart = part->second;
-                  for (MusECore::iEvent i = events->begin(); i != events->end(); ++i) {
+                  for (MusECore::ciEvent i = events.begin(); i != events.end(); ++i) {
                         MusECore::Event event = i->second;
                         if(event.type() != MusECore::Controller && event.type() != MusECore::Note)
                           continue;
@@ -1058,9 +1057,9 @@ void DrumCanvas::mapChanged(int spitch, int dpitch)
                         }
                         
                         if (pitch == spitch) {
-                              MusECore::Event* spitch_event = &(i->second);
-                              delete_events.push_back(std::pair<MusECore::Part*, MusECore::Event*>(thePart, spitch_event));
-                              MusECore::Event newEvent = spitch_event->clone();
+                              const MusECore::Event& spitch_event = i->second;
+                              delete_events.push_back(std::pair<MusECore::Part*, MusECore::Event>(thePart, spitch_event));
+                              MusECore::Event newEvent = spitch_event.clone();
                               if(drc)
                                 newEvent.setA((newEvent.dataA() & ~0xff) | dpitch);
                               else
@@ -1068,9 +1067,9 @@ void DrumCanvas::mapChanged(int spitch, int dpitch)
                               add_events.push_back(std::pair<MusECore::Part*, MusECore::Event>(thePart, newEvent));
                               }
                         else if (pitch == dpitch) {
-                              MusECore::Event* dpitch_event = &(i->second);
-                              delete_events.push_back(std::pair<MusECore::Part*, MusECore::Event*>(thePart, dpitch_event));
-                              MusECore::Event newEvent = dpitch_event->clone();
+                              const MusECore::Event& dpitch_event = i->second;
+                              delete_events.push_back(std::pair<MusECore::Part*, MusECore::Event>(thePart, dpitch_event));
+                              MusECore::Event newEvent = dpitch_event.clone();
                               if(drc)
                                 newEvent.setA((newEvent.dataA() & ~0xff) | spitch);
                               else
@@ -1083,8 +1082,8 @@ void DrumCanvas::mapChanged(int spitch, int dpitch)
 
       for (idel_ev i = delete_events.begin(); i != delete_events.end(); i++) {
             MusECore::Part*  thePart = (*i).first;
-            MusECore::Event* theEvent = (*i).second;
-            operations.push_back(MusECore::UndoOp(MusECore::UndoOp::DeleteEvent, *theEvent, thePart, true, false));
+            const MusECore::Event& theEvent = (*i).second;
+            operations.push_back(MusECore::UndoOp(MusECore::UndoOp::DeleteEvent, theEvent, thePart, true, false));
             }
 
       MusECore::DrumMap dm = MusEGlobal::drumMap[spitch];
@@ -1212,9 +1211,8 @@ void DrumCanvas::resizeEvent(QResizeEvent* ev)
 
 void DrumCanvas::modifySelected(NoteInfo::ValType type, int val, bool delta_mode)
       {
-      QList< QPair<MusECore::EventList*,MusECore::Event> > already_done;
-      MusEGlobal::audio->msgIdle(true);
-      MusEGlobal::song->startUndo();
+      QList< QPair<int,MusECore::Event> > already_done;
+      MusECore::Undo operations;
       for (iCItem i = items.begin(); i != items.end(); ++i) {
             if (!(i->second->isSelected()))
                   continue;
@@ -1225,7 +1223,7 @@ void DrumCanvas::modifySelected(NoteInfo::ValType type, int val, bool delta_mode
 
             MusECore::MidiPart* part = (MusECore::MidiPart*)(e->part());
 
-            if (already_done.contains(QPair<MusECore::EventList*,MusECore::Event>(part->events(), event)))
+            if (already_done.contains(QPair<int,MusECore::Event>(part->clonemaster_sn(), event)))
               continue;
             
             MusECore::Event newEvent = event.clone();
@@ -1303,14 +1301,12 @@ void DrumCanvas::modifySelected(NoteInfo::ValType type, int val, bool delta_mode
                         }
                         break;
                   }
-            MusEGlobal::song->changeEvent(event, newEvent, part);
-            // Indicate do not do port controller values and clone parts. 
-            MusEGlobal::song->addUndo(MusECore::UndoOp(MusECore::UndoOp::ModifyEvent, newEvent, event, part, false, false));
 
-            already_done.append(QPair<MusECore::EventList*,MusECore::Event>(part->events(), event));
+            operations.push_back(MusECore::UndoOp(MusECore::UndoOp::ModifyEvent, newEvent, event, part, false, false));
+
+            already_done.append(QPair<int,MusECore::Event>(part->clonemaster_sn(), event));
             }
-      MusEGlobal::song->endUndo(SC_EVENT_MODIFIED);
-      MusEGlobal::audio->msgIdle(false);
+      MusEGlobal::song->applyOperationGroup(operations);
       }
 
 //---------------------------------------------------------
@@ -1481,18 +1477,17 @@ void DrumCanvas::setStep(int v)
 //---------------------------------------------------------
 //   getEventAtCursorPos
 //---------------------------------------------------------
-MusECore::Event *DrumCanvas::getEventAtCursorPos()
+const MusECore::Event* DrumCanvas::getEventAtCursorPos()
 {
     if (_tool != CursorTool)
       return 0;
     if (instrument_map[cursorPos.y()].tracks.contains(curPart->track()))
     {
-      MusECore::EventList* el = curPart->events();
-      MusECore::iEvent lower  = el->lower_bound(cursorPos.x()-curPart->tick());
-      MusECore::iEvent upper  = el->upper_bound(cursorPos.x()-curPart->tick());
+      MusECore::ciEvent lower  = curPart->events().lower_bound(cursorPos.x()-curPart->tick());
+      MusECore::ciEvent upper  = curPart->events().upper_bound(cursorPos.x()-curPart->tick());
       int curPitch = instrument_map[cursorPos.y()].pitch;
-      for (MusECore::iEvent i = lower; i != upper; ++i) {
-        MusECore::Event &ev = i->second;
+      for (MusECore::ciEvent i = lower; i != upper; ++i) {
+        const MusECore::Event& ev = i->second;
         if (ev.isNote()  &&  ev.pitch() == curPitch)
           return &ev;
       }
@@ -1503,7 +1498,7 @@ MusECore::Event *DrumCanvas::getEventAtCursorPos()
 //---------------------------------------------------------
 //   selectCursorEvent
 //---------------------------------------------------------
-void DrumCanvas::selectCursorEvent(MusECore::Event *ev)
+void DrumCanvas::selectCursorEvent(const MusECore::Event* ev)
 {
   for (iCItem i = items.begin(); i != items.end(); ++i)
   {
diff --git a/muse2/muse/midiedit/dcanvas.h b/muse2/muse/midiedit/dcanvas.h
index 1a1ee546..300f2291 100644
--- a/muse2/muse/midiedit/dcanvas.h
+++ b/muse2/muse/midiedit/dcanvas.h
@@ -130,7 +130,7 @@ class DrumCanvas : public EventCanvas {
       void dragEnterEvent(QDragEnterEvent* event);
       void dragMoveEvent(QDragMoveEvent*);
       void dragLeaveEvent(QDragLeaveEvent*);
-      virtual CItem* addItem(MusECore::Part*, MusECore::Event&);
+      virtual CItem* addItem(MusECore::Part*, const MusECore::Event&);
       virtual void resizeEvent(QResizeEvent*);
       virtual void curPartChanged();
       int getNextStep(unsigned int pos, int basicStep, int stepSize=1);
@@ -167,8 +167,8 @@ class DrumCanvas : public EventCanvas {
       virtual void modifySelected(NoteInfo::ValType type, int val, bool delta_mode = true);
       virtual void keyPress(QKeyEvent* event);
       virtual void keyRelease(QKeyEvent* event);
-      MusECore::Event *getEventAtCursorPos();
-      void selectCursorEvent(MusECore::Event *ev);
+      const MusECore::Event* getEventAtCursorPos();
+      void selectCursorEvent(const MusECore::Event* ev);
 
       int pitch_and_track_to_instrument(int pitch, MusECore::Track* track);
 
diff --git a/muse2/muse/midiedit/dlist.cpp b/muse2/muse/midiedit/dlist.cpp
index 09b33735..ecfc02ba 100644
--- a/muse2/muse/midiedit/dlist.cpp
+++ b/muse2/muse/midiedit/dlist.cpp
@@ -208,8 +208,7 @@ void DList::draw(QPainter& p, const QRect& rect)
                                           continue;
 
                                         found = true;
-                                        MusECore::EventList* el = cur_part->events();
-                                        for(MusECore::iEvent ie = el->begin(); ie != el->end(); ++ie)
+                                        for(MusECore::ciEvent ie = cur_part->events().begin(); ie != cur_part->events().end(); ++ie)
                                         {
                                           MusECore::Event e = ie->second;
                                           if(e.type() != MusECore::Controller)
@@ -303,14 +302,14 @@ void DList::draw(QPainter& p, const QRect& rect)
                                               continue;
 
                                             found = true;
-                                            MusECore::EventList* el = cur_part->events();
+                                            const MusECore::EventList& el = cur_part->events();
                                             //MusECore::PartList* part_list = dcanvas->drumEdit()->parts();
                                             //for(MusECore::ciPart ip = part_list->cbegin(); ip != part_list->cend(); ++ip)
                                             {
                                               //MusECore::Part* part = ip->second;
                                               ///if(part->track() != 
-                                              //MusECore::EventList* el = part->events();
-                                              for(MusECore::iEvent ie = el->begin(); ie != el->end(); ++ie)
+                                              //const MusECore::EventList& el = part->events();
+                                              for(MusECore::ciEvent ie = el.begin(); ie != el.end(); ++ie)
                                               {
                                                 MusECore::Event e = ie->second;
                                                 if(e.type() != MusECore::Controller)
diff --git a/muse2/muse/midiedit/drumedit.cpp b/muse2/muse/midiedit/drumedit.cpp
index a93ad01e..175287cb 100644
--- a/muse2/muse/midiedit/drumedit.cpp
+++ b/muse2/muse/midiedit/drumedit.cpp
@@ -1850,8 +1850,8 @@ void DrumEdit::hideUnusedInstruments()
     for (MusECore::ciPart p = parts()->begin(); p != parts()->end(); ++p)
       if (p->second->track() == track)
       {
-        const EventList* el = p->second->cevents();
-        for (ciEvent ev=el->begin(); ev!=el->end(); ev++)
+        const EventList& el = p->second->events();
+        for (ciEvent ev=el.begin(); ev!=el.end(); ev++)
           hide[ev->second.pitch()]=false;
       }
     
@@ -1883,8 +1883,8 @@ void DrumEdit::hideEmptyInstruments()
     for (MusECore::ciPart p = parts()->begin(); p != parts()->end(); ++p)
       if (p->second->track() == track)
       {
-        const EventList* el = p->second->cevents();
-        for (ciEvent ev=el->begin(); ev!=el->end(); ev++)
+        const EventList& el = p->second->events();
+        for (ciEvent ev=el.begin(); ev!=el.end(); ev++)
           hide[ev->second.pitch()]=false;
       }
     
diff --git a/muse2/muse/midiedit/ecanvas.cpp b/muse2/muse/midiedit/ecanvas.cpp
index 4ae702f1..d70cc50c 100644
--- a/muse2/muse/midiedit/ecanvas.cpp
+++ b/muse2/muse/midiedit/ecanvas.cpp
@@ -192,8 +192,7 @@ void EventCanvas::songChanged(MusECore::SongChangedFlags_t flags)
                   if (etick > end_tick)
                         end_tick = etick;
 
-                  MusECore::EventList* el = part->events();
-                  for (MusECore::iEvent i = el->begin(); i != el->end(); ++i) {
+                  for (MusECore::ciEvent i = part->events().begin(); i != part->events().end(); ++i) {
                         MusECore::Event e = i->second;
                         // Do not add events which are past the end of the part.
                         if(e.tick() > len)      
diff --git a/muse2/muse/midiedit/ecanvas.h b/muse2/muse/midiedit/ecanvas.h
index 95e856c8..e7d7ad6e 100644
--- a/muse2/muse/midiedit/ecanvas.h
+++ b/muse2/muse/midiedit/ecanvas.h
@@ -80,7 +80,7 @@ class EventCanvas : public Canvas {
       bool _setCurPartIfOnlyOneEventIsSelected;
 
       void updateSelection();
-      virtual CItem* addItem(MusECore::Part*, MusECore::Event&) = 0;
+      virtual CItem* addItem(MusECore::Part*, const MusECore::Event&) = 0;
       virtual QPoint raster(const QPoint&) const;
       virtual MusECore::Undo moveCanvasItems(CItemList&, int, int, DragType, bool rasterize = true) = 0;
       virtual bool moveItem(MusECore::Undo&, CItem*, const QPoint&, DragType, bool rasterize = true) = 0;
diff --git a/muse2/muse/midiedit/piano.cpp b/muse2/muse/midiedit/piano.cpp
index 40d93910..17553baa 100644
--- a/muse2/muse/midiedit/piano.cpp
+++ b/muse2/muse/midiedit/piano.cpp
@@ -570,8 +570,7 @@ void Piano::draw(QPainter& p, const QRect& r)
         int num = cl->num();
         int pitch = num & 0x7f;
         bool used = false;
-        MusECore::EventList* el = cur_part->events();
-        for (MusECore::ciEvent ie = el->begin(); ie != el->end(); ++ie)
+        for (MusECore::ciEvent ie = cur_part->events().begin(); ie != cur_part->events().end(); ++ie)
         {
           MusECore::Event e = ie->second;
           if(e.type() != MusECore::Controller)
diff --git a/muse2/muse/midiedit/prcanvas.cpp b/muse2/muse/midiedit/prcanvas.cpp
index 92ed3758..5be4c090 100644
--- a/muse2/muse/midiedit/prcanvas.cpp
+++ b/muse2/muse/midiedit/prcanvas.cpp
@@ -59,7 +59,7 @@ namespace MusEGui {
 //   NEvent
 //---------------------------------------------------------
 
-NEvent::NEvent(MusECore::Event& e, MusECore::Part* p, int y) : MusEGui::CItem(e, p)
+NEvent::NEvent(const MusECore::Event& e, MusECore::Part* p, int y) : MusEGui::CItem(e, p)
       {
       y = y - KH/4;
       unsigned tick = e.tick() + p->tick();
@@ -72,7 +72,7 @@ NEvent::NEvent(MusECore::Event& e, MusECore::Part* p, int y) : MusEGui::CItem(e,
 //   addItem
 //---------------------------------------------------------
 
-CItem* PianoCanvas::addItem(MusECore::Part* part, MusECore::Event& event)
+CItem* PianoCanvas::addItem(MusECore::Part* part, const MusECore::Event& event)
       {
       if (signed(event.tick())<0) {
             printf("ERROR: trying to add event before current part!\n");
@@ -635,11 +635,10 @@ void PianoCanvas::pianoCmd(int cmd)
                   if (part == 0)
                         break;
 
-                  MusECore::EventList* el = part->events();
                   MusECore::Undo operations;
 
                   std::list <MusECore::Event> elist;
-                  for (MusECore::iEvent e = el->lower_bound(pos[0] - part->tick()); e != el->end(); ++e)
+                  for (MusECore::ciEvent e = part->events().lower_bound(pos[0] - part->tick()); e != part->events().end(); ++e)
                         elist.push_back((MusECore::Event)e->second);
                   for (std::list<MusECore::Event>::iterator i = elist.begin(); i != elist.end(); ++i) {
                         MusECore::Event event = *i;
@@ -663,10 +662,8 @@ void PianoCanvas::pianoCmd(int cmd)
                         break;
                   
                   MusECore::Undo operations;
-                  MusECore::EventList* el = part->events();
-
                   std::list<MusECore::Event> elist;
-                  for (MusECore::iEvent e = el->lower_bound(pos[0]); e != el->end(); ++e)
+                  for (MusECore::ciEvent e = part->events().lower_bound(pos[0]); e != part->events().end(); ++e)
                         elist.push_back((MusECore::Event)e->second);
                   for (std::list<MusECore::Event>::iterator i = elist.begin(); i != elist.end(); ++i) {
                         MusECore::Event event = *i;
@@ -989,7 +986,7 @@ void PianoCanvas::curPartChanged()
 
 void PianoCanvas::modifySelected(MusEGui::NoteInfo::ValType type, int val, bool delta_mode)
       {
-      QList< QPair<MusECore::EventList*,MusECore::Event> > already_done;
+      QList< QPair<int,MusECore::Event> > already_done;
       MusEGlobal::audio->msgIdle(true);
       MusEGlobal::song->startUndo();
       for (MusEGui::iCItem i = items.begin(); i != items.end(); ++i) {
@@ -1002,7 +999,7 @@ void PianoCanvas::modifySelected(MusEGui::NoteInfo::ValType type, int val, bool
 
             MusECore::MidiPart* part = (MusECore::MidiPart*)(e->part());
             
-            if (already_done.contains(QPair<MusECore::EventList*,MusECore::Event>(part->events(), event)))
+            if (already_done.contains(QPair<int,MusECore::Event>(part->clonemaster_sn(), event)))
               continue;
             
             MusECore::Event newEvent = event.clone();
@@ -1072,7 +1069,7 @@ void PianoCanvas::modifySelected(MusEGui::NoteInfo::ValType type, int val, bool
             // Indicate do not do port controller values and clone parts. 
             MusEGlobal::song->addUndo(MusECore::UndoOp(MusECore::UndoOp::ModifyEvent, newEvent, event, part, false, false));
 
-            already_done.append(QPair<MusECore::EventList*,MusECore::Event>(part->events(), event));
+            already_done.append(QPair<int,MusECore::Event>(part->clonemaster_sn(), event));
             }
       MusEGlobal::song->endUndo(SC_EVENT_MODIFIED);
       MusEGlobal::audio->msgIdle(false);
diff --git a/muse2/muse/midiedit/prcanvas.h b/muse2/muse/midiedit/prcanvas.h
index 888427ea..4748093b 100644
--- a/muse2/muse/midiedit/prcanvas.h
+++ b/muse2/muse/midiedit/prcanvas.h
@@ -46,7 +46,7 @@ namespace MusEGui {
 
 class NEvent : public CItem {
    public:
-      NEvent(MusECore::Event& e, MusECore::Part* p, int y);
+      NEvent(const MusECore::Event& e, MusECore::Part* p, int y);
       };
 
 class ScrollScale;
@@ -80,7 +80,7 @@ class PianoCanvas : public EventCanvas {
       virtual void dragEnterEvent(QDragEnterEvent* event);
       virtual void dragMoveEvent(QDragMoveEvent*);
       virtual void dragLeaveEvent(QDragLeaveEvent*);
-      virtual CItem* addItem(MusECore::Part*, MusECore::Event&);
+      virtual CItem* addItem(MusECore::Part*, const MusECore::Event&);
 
       int y2pitch(int) const;
       int pitch2y(int) const;
diff --git a/muse2/muse/midiedit/scoreedit.cpp b/muse2/muse/midiedit/scoreedit.cpp
index 543e86aa..954cd08a 100644
--- a/muse2/muse/midiedit/scoreedit.cpp
+++ b/muse2/muse/midiedit/scoreedit.cpp
@@ -73,6 +73,8 @@ using namespace std;
 
 using MusEGlobal::debugMsg;
 using MusEGlobal::heavyDebugMsg;
+using MusECore::UndoOp;
+using MusECore::Undo;
 
 namespace MusEGui {
 
@@ -519,7 +521,7 @@ ScoreEdit::ScoreEdit(QWidget* parent, const char* name, unsigned initPos)
 	selection_changed();
 
 	connect(MusEGlobal::song, SIGNAL(songChanged(MusECore::SongChangedFlags_t)), SLOT(song_changed(MusECore::SongChangedFlags_t)));	
-	connect(MusEGlobal::song, SIGNAL(newPartsCreated(const std::map< MusECore::Part*, std::set<MusECore::Part*> >&)), score_canvas, SLOT(add_new_parts(const std::map< MusECore::Part*, std::set<MusECore::Part*> >&)));	
+	connect(MusEGlobal::song, SIGNAL(newPartsCreated(const std::map< const MusECore::Part*, std::set<const MusECore::Part*> >&)), score_canvas, SLOT(add_new_parts(const std::map< const MusECore::Part*, std::set<const MusECore::Part*> >&)));	
 
 	score_canvas->fully_recalculate();
 	score_canvas->goto_tick(initPos,true);
@@ -653,7 +655,7 @@ void ScoreEdit::song_changed(MusECore::SongChangedFlags_t flags)
 	
 	if (flags & (SC_SELECTION | SC_EVENT_MODIFIED | SC_EVENT_REMOVED))
 	{
-		map<MusECore::Event*, MusECore::Part*> selection=get_events(score_canvas->get_all_parts(),1);
+		map<const MusECore::Event*, const MusECore::Part*> selection=get_events(score_canvas->get_all_parts(),1);
 		if (selection.empty())
 		{
 			apply_velo_to_label->setText(tr("Apply to new notes:"));
@@ -664,7 +666,7 @@ void ScoreEdit::song_changed(MusECore::SongChangedFlags_t flags)
 			
 			int velo=-1;
 			int velo_off=-1;
-			for (map<MusECore::Event*, MusECore::Part*>::iterator it=selection.begin(); it!=selection.end(); it++)
+			for (map<const MusECore::Event*, const MusECore::Part*>::iterator it=selection.begin(); it!=selection.end(); it++)
 				if (it->first->type()==MusECore::Note)
 				{
 					if (velo==-1) velo=it->first->velo();
@@ -897,7 +899,7 @@ void staff_t::write_status(int level, MusECore::Xml& xml) const
 	xml.tag(level++, "staff");
 	xml.intTag(level, "type", type);
 	xml.intTag(level, "clef", clef);
-	for (set<MusECore::Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
+	for (set<const MusECore::Part*>::iterator part=parts.begin(); part!=parts.end(); part++)
 	{
 		MusECore::Track* track = (*part)->track();
 		int trkIdx   = MusEGlobal::song->tracks()->index(track);
@@ -962,7 +964,7 @@ void ScoreEdit::writeStatus(int level, MusECore::Xml& xml) const
 	xml.intTag(level, "preambleContainsKeysig", preamble_keysig_action->isChecked());
 	xml.intTag(level, "preambleContainsTimesig", preamble_timesig_action->isChecked());
 
-	MusECore::Part* selected_part=score_canvas->get_selected_part();
+	const MusECore::Part* selected_part=score_canvas->get_selected_part();
 	if (selected_part==NULL)
 	{
 		xml.put(level, "<selectedPart>none</selectedPart>");
@@ -1520,9 +1522,9 @@ void ScoreCanvas::move_staff_below(list<staff_t>::iterator dest, list<staff_t>::
 	move_staff_above(dest, src);
 }
 
-set<MusECore::Part*> ScoreCanvas::get_all_parts()
+set<const MusECore::Part*> ScoreCanvas::get_all_parts()
 {
-	set<MusECore::Part*> result;
+	set<const MusECore::Part*> result;
 	
 	for (list<staff_t>::iterator it=staves.begin(); it!=staves.end(); it++)
 		result.insert(it->parts.begin(), it->parts.end());
@@ -1784,14 +1786,13 @@ void staff_t::create_appropriate_eventlist()
 	// phase one: fill the list -----------------------------------------
 	
 	//insert note on events
-	for (set<MusECore::Part*>::const_iterator part_it=parts.begin(); part_it!=parts.end(); part_it++)
+	for (set<const MusECore::Part*>::const_iterator part_it=parts.begin(); part_it!=parts.end(); part_it++)
 	{
-		MusECore::Part* part=*part_it;
-		MusECore::EventList* el=part->events();
+		const MusECore::Part* part=*part_it;
 		
-		for (MusECore::iEvent it=el->begin(); it!=el->end(); it++)
+		for (MusECore::ciEvent it=part->events().begin(); it!=part->events().end(); it++)
 		{
-			MusECore::Event& event=it->second;
+			const MusECore::Event& event=it->second;
 			
 			if ( ( event.isNote() && !event.isNoteOff() &&
 			       // (event.endTick() <= part->lenTick()) ) &&
@@ -3804,7 +3805,7 @@ void ScoreCanvas::mousePressEvent (QMouseEvent* event)
 				
 				if ((mouse_erases_notes) || (event->button()==Qt::MidButton)) //erase?
 				{
-					MusEGlobal::audio->msgDeleteEvent(dragged_event, dragged_event_part, true, false, false);
+					MusEGlobal::song->applyOperation(UndoOp(UndoOp::DeleteEvent,dragged_event, dragged_event_part,  false, false));
 				}
 				else if (event->button()==Qt::LeftButton) //edit?
 				{
@@ -3818,8 +3819,8 @@ void ScoreCanvas::mousePressEvent (QMouseEvent* event)
 				{
 					if (mouse_inserts_notes)
 					{
-						MusECore::Part* curr_part = NULL;
-						set<MusECore::Part*> possible_dests=staff_it->parts_at_tick(tick);
+						const MusECore::Part* curr_part = NULL;
+						set<const MusECore::Part*> possible_dests=staff_it->parts_at_tick(tick);
 
 						if (!possible_dests.empty())
 						{
@@ -3866,7 +3867,7 @@ void ScoreCanvas::mousePressEvent (QMouseEvent* event)
 								newevent.setLenTick(curr_part->lenTick() - newevent.tick());
 							}
 							
-							MusEGlobal::audio->msgAddEvent(newevent, curr_part, true, false, false);
+							MusEGlobal::song->applyOperation(UndoOp(UndoOp::AddEvent, newevent, curr_part,false, false));
 							
 							set_dragged_event_part(curr_part);
 							dragged_event=newevent;
@@ -3913,7 +3914,7 @@ void ScoreCanvas::mouseReleaseEvent (QMouseEvent* event)
 			{
 				if (debugMsg) cout << "new length <= 0, erasing item" << endl;
 				if (undo_started) MusEGlobal::song->undo();
-				MusEGlobal::audio->msgDeleteEvent(dragged_event, dragged_event_part, true, false, false);
+				MusEGlobal::song->applyOperation(UndoOp(UndoOp::DeleteEvent,dragged_event, dragged_event_part, false, false));
 			}
 			else
 			{
@@ -3928,9 +3929,7 @@ void ScoreCanvas::mouseReleaseEvent (QMouseEvent* event)
 				if (!ctrl)
 					deselect_all();
 
-			clicked_event_ptr->setSelected(!clicked_event_ptr->selected());
-
-			MusEGlobal::song->update(SC_SELECTION);
+			MusEGlobal::song->applyOperation(UndoOp(UndoOp::SelectEvent, *clicked_event_ptr, !clicked_event_ptr->selected(), clicked_event_ptr->selected()));
 		}
 		
 		setMouseTracking(false);
@@ -3971,7 +3970,7 @@ void ScoreCanvas::mouseReleaseEvent (QMouseEvent* event)
 		if (!ctrl)
 			deselect_all();
 		
-		set<MusECore::Event*> already_processed;
+		set<const MusECore::Event*> already_processed;
 		
 		for (list<staff_t>::iterator it=staves.begin(); it!=staves.end(); it++)
 			it->apply_lasso(lasso.translated(x_pos-x_left, y_pos - it->y_draw), already_processed);
@@ -4029,9 +4028,7 @@ void ScoreCanvas::mouseMoveEvent (QMouseEvent* event)
 					if (!ctrl)
 						deselect_all();
 					
-					clicked_event_ptr->setSelected(true);
-					
-					MusEGlobal::song->update(SC_SELECTION);
+					MusEGlobal::song->applyOperation(UndoOp(UndoOp::SelectEvent, *clicked_event_ptr, true, clicked_event_ptr->selected()));
 				}
 				
 				old_pitch=-1;
@@ -4505,20 +4502,23 @@ void ScoreCanvas::set_velo_off(int velo)
 
 void ScoreCanvas::deselect_all()
 {
-	set<MusECore::Part*> all_parts=get_all_parts();
+	set<const MusECore::Part*> all_parts=get_all_parts();
+	
+	Undo operations;
+	operations.combobreaker=true;
 
-	for (set<MusECore::Part*>::iterator part=all_parts.begin(); part!=all_parts.end(); part++)
-		for (MusECore::iEvent event=(*part)->events()->begin(); event!=(*part)->events()->end(); event++)
-			event->second.setSelected(false);
+	for (set<const MusECore::Part*>::iterator part=all_parts.begin(); part!=all_parts.end(); part++)
+		for (MusECore::ciEvent event=(*part)->events().begin(); event!=(*part)->events().end(); event++)
+			operations.push_back(UndoOp(UndoOp::SelectEvent, event->second, false, event->second.selected()));
 	
-	MusEGlobal::song->update(SC_SELECTION);
+	MusEGlobal::song->applyOperationGroup(operations);
 }
 
 bool staff_t::cleanup_parts()
 {
 	bool did_something=false;
 	
-	for (set<MusECore::Part*>::iterator it=parts.begin(); it!=parts.end();)
+	for (set<const MusECore::Part*>::iterator it=parts.begin(); it!=parts.end();)
 	{
 		bool valid=false;
 		
@@ -4549,18 +4549,18 @@ bool staff_t::cleanup_parts()
 	return did_something;
 }
 
-set<MusECore::Part*> staff_t::parts_at_tick(unsigned tick)
+set<const MusECore::Part*> staff_t::parts_at_tick(unsigned tick)
 {
-	set<MusECore::Part*> result;
+	set<const MusECore::Part*> result;
 	
-	for (set<MusECore::Part*>::iterator it=parts.begin(); it!=parts.end(); it++)
+	for (set<const MusECore::Part*>::iterator it=parts.begin(); it!=parts.end(); it++)
 		if ((tick >= (*it)->tick()) && (tick<=(*it)->endTick()))
 			result.insert(*it);
 	
 	return result;
 }
 
-void staff_t::apply_lasso(QRect rect, set<MusECore::Event*>& already_processed)
+void staff_t::apply_lasso(QRect rect, set<const MusECore::Event*>& already_processed)
 {
 	for (ScoreItemList::iterator it=itemlist.begin(); it!=itemlist.end(); it++)
 		for (set<FloItem>::iterator it2=it->second.begin(); it2!=it->second.end(); it2++)
@@ -4569,7 +4569,7 @@ void staff_t::apply_lasso(QRect rect, set<MusECore::Event*>& already_processed)
 				if (rect.contains(it2->x, it2->y))
 					if (already_processed.find(it2->source_event)==already_processed.end())
 					{
-						it2->source_event->setSelected(!it2->source_event->selected());
+						MusEGlobal::song->applyOperation(UndoOp(UndoOp::SelectEvent,*it2->source_event,!it2->source_event->selected(),it2->source_event->selected()));
 						already_processed.insert(it2->source_event);
 					}
 			}
@@ -4617,7 +4617,7 @@ void staff_t::update_part_indices()
 {
 	part_indices.clear();
 	
-	for (set<MusECore::Part*>::iterator it=parts.begin(); it!=parts.end(); it++)
+	for (set<const MusECore::Part*>::iterator it=parts.begin(); it!=parts.end(); it++)
 		part_indices.insert((*it)->sn());
 }
 
@@ -4654,15 +4654,15 @@ void ScoreEdit::keyPressEvent(QKeyEvent* event)
 }
 
 
-void ScoreCanvas::add_new_parts(const std::map< MusECore::Part*, std::set<MusECore::Part*> >& param)
+void ScoreCanvas::add_new_parts(const std::map< const MusECore::Part*, std::set<const MusECore::Part*> >& param)
 {
 	for (list<staff_t>::iterator staff=staves.begin(); staff!=staves.end(); staff++)
 	{
-		for (std::map< MusECore::Part*, set<MusECore::Part*> >::const_iterator it = param.begin(); it!=param.end(); it++)
+		for (std::map< const MusECore::Part*, set<const MusECore::Part*> >::const_iterator it = param.begin(); it!=param.end(); it++)
 			if (staff->parts.find(it->first)!=staff->parts.end())
 				staff->parts.insert(it->second.begin(), it->second.end());
 		
-		//staff->cleanup_parts(); // don't cleanup here, because at this point, the parts may only exist
+		//staff->cleanup_parts(); // don't cleanup here, because at this point, the parts might exist only
 		                          // in the operation group. cleanup could remove them immediately
 		staff->update_part_indices();
 	}
diff --git a/muse2/muse/midiedit/scoreedit.h b/muse2/muse/midiedit/scoreedit.h
index 3b413660..31bc0cff 100644
--- a/muse2/muse/midiedit/scoreedit.h
+++ b/muse2/muse/midiedit/scoreedit.h
@@ -257,8 +257,8 @@ class FloEvent
 		enum typeEnum { NOTE_ON = 30, NOTE_OFF = 10, BAR = 20, KEY_CHANGE=23, TIME_SIG=26 }; //the order matters!
 		typeEnum type;
 		unsigned tick;
-		MusECore::Part* source_part;
-		MusECore::Event* source_event;
+		const MusECore::Part* source_part;
+		const MusECore::Event* source_event;
 		
 		int pitch;
 		mutable int vel;
@@ -270,7 +270,7 @@ class FloEvent
 		MusECore::key_enum key;
 		
 		
-		FloEvent(unsigned ti, int p,int v,int l,typeEnum t, MusECore::Part* part=NULL, MusECore::Event* event=NULL)
+		FloEvent(unsigned ti, int p,int v,int l,typeEnum t, const MusECore::Part* part=NULL, const MusECore::Event* event=NULL)
 		{
 			pitch=p;
 			vel=v;
@@ -312,8 +312,8 @@ class FloItem
 		enum typeEnum { NOTE=21, REST=22, NOTE_END=01, REST_END=02, BAR =10, KEY_CHANGE=13, TIME_SIG=16}; //the order matters!
 		typeEnum type;
 		unsigned begin_tick;
-		MusECore::Event* source_event;
-		MusECore::Part* source_part;
+		const MusECore::Event* source_event;
+		const MusECore::Part* source_part;
 		
 		note_pos_t pos;
 		int len;
@@ -343,7 +343,7 @@ class FloItem
 		
 
 		
-		FloItem(typeEnum t, note_pos_t p, int l=0,int d=0, bool ti=false, unsigned beg=0, MusECore::Part* part=NULL, MusECore::Event* event=NULL)
+		FloItem(typeEnum t, note_pos_t p, int l=0,int d=0, bool ti=false, unsigned beg=0, const MusECore::Part* part=NULL, const MusECore::Event* event=NULL)
 		{
 			pos=p;
 			dots=d;
@@ -546,7 +546,7 @@ enum staff_mode_t
 
 struct staff_t
 {
-	set<MusECore::Part*> parts;
+	set<const MusECore::Part*> parts;
 	set<int> part_indices;
 	ScoreEventList eventlist;
 	ScoreItemList itemlist;
@@ -568,7 +568,7 @@ struct staff_t
 	void process_itemlist();
 	void calc_item_pos();
 	
-	void apply_lasso(QRect rect, set<MusECore::Event*>& already_processed);
+	void apply_lasso(QRect rect, set<const MusECore::Event*>& already_processed);
 	
 	void recalculate()
 	{
@@ -585,7 +585,7 @@ struct staff_t
 		parent=parent_;
 	}
 	
-	staff_t (ScoreCanvas* parent_, staff_type_t type_, clef_t clef_, set<MusECore::Part*> parts_)
+	staff_t (ScoreCanvas* parent_, staff_type_t type_, clef_t clef_, set<const MusECore::Part*> parts_)
 	{
 		type=type_;
 		clef=clef_;
@@ -596,7 +596,7 @@ struct staff_t
 	
 	bool cleanup_parts();
 	
-	set<MusECore::Part*> parts_at_tick(unsigned tick);
+	set<const MusECore::Part*> parts_at_tick(unsigned tick);
 	
 	void read_status(MusECore::Xml& xml);
 	void write_status(int level, MusECore::Xml& xml) const;
@@ -718,7 +718,7 @@ class ScoreCanvas : public MusEGui::View
 		float y_scroll_speed;
 		float y_scroll_pos;
 
-		MusECore::Part* selected_part;
+		const MusECore::Part* selected_part;
 		int selected_part_index;
 		
 		int last_len;
@@ -742,11 +742,11 @@ class ScoreCanvas : public MusEGui::View
 		bool inserting;
 		bool dragging;
 		bool drag_cursor_changed;
-		MusECore::Part* dragged_event_part;
+		const MusECore::Part* dragged_event_part;
 		int dragged_event_part_index;
 		MusECore::Event dragged_event;
 		MusECore::Event original_dragged_event;
-		MusECore::Event* clicked_event_ptr;
+		const MusECore::Event* clicked_event_ptr;
 		
 		int old_pitch;
 		unsigned old_dest_tick;
@@ -790,7 +790,7 @@ class ScoreCanvas : public MusEGui::View
 		void deselect_all();
 		void midi_note(int pitch, int velo);
 		
-		void add_new_parts(const std::map< MusECore::Part*, std::set<MusECore::Part*> >&);
+		void add_new_parts(const std::map< const MusECore::Part*, std::set<const MusECore::Part*> >&);
 
 	public slots:
 		void x_scroll_event(int);
@@ -855,12 +855,12 @@ class ScoreCanvas : public MusEGui::View
 		int get_last_len() {return last_len;}
 		void set_last_len(int l) {last_len=l;}
 		
-		MusECore::Part* get_selected_part() {return selected_part;}
-		void set_selected_part(MusECore::Part* p) {selected_part=p; if (selected_part) selected_part_index=selected_part->sn();}
-		MusECore::Part* get_dragged_event_part() {return dragged_event_part;}
-		void set_dragged_event_part(MusECore::Part* p) {dragged_event_part=p; if (dragged_event_part) dragged_event_part_index=dragged_event_part->sn();}
+		const MusECore::Part* get_selected_part() const {return selected_part;}
+		void set_selected_part(const MusECore::Part* p) {selected_part=p; if (selected_part) selected_part_index=selected_part->sn();}
+		const MusECore::Part* get_dragged_event_part() const {return dragged_event_part;}
+		void set_dragged_event_part(const MusECore::Part* p) {dragged_event_part=p; if (dragged_event_part) dragged_event_part_index=dragged_event_part->sn();}
 		
-		set<MusECore::Part*> get_all_parts();
+		set<const MusECore::Part*> get_all_parts();
 		
 		void write_staves(int level, MusECore::Xml& xml) const;
 
diff --git a/muse2/muse/midieditor.cpp b/muse2/muse/midieditor.cpp
index 13e6edc5..a4052d90 100644
--- a/muse2/muse/midieditor.cpp
+++ b/muse2/muse/midieditor.cpp
@@ -62,7 +62,7 @@ MidiEditor::MidiEditor(ToplevelType t, int r, MusECore::PartList* pl,
       mainGrid->setSpacing(0);  
       setCentralWidget(mainw);
       
-      connect(MusEGlobal::song, SIGNAL(newPartsCreated(const std::map< MusECore::Part*, std::set<MusECore::Part*> >&)), SLOT(addNewParts(const std::map< MusECore::Part*, std::set<MusECore::Part*> >&)));	
+      connect(MusEGlobal::song, SIGNAL(newPartsCreated(const std::map< const MusECore::Part*, std::set<const MusECore::Part*> >&)), SLOT(addNewParts(const std::map< const MusECore::Part*, std::set<const MusECore::Part*> >&)));
       }
 
 //---------------------------------------------------------
@@ -245,15 +245,15 @@ void MidiEditor::setCurCanvasPart(MusECore::Part* part)
     canvas->setCurrentPart(part); 
 }
 
-void MidiEditor::addNewParts(const std::map< MusECore::Part*, std::set<MusECore::Part*> >& param)
+void MidiEditor::addNewParts(const std::map< const MusECore::Part*, std::set<const MusECore::Part*> >& param)
 {
   using std::map;
   using std::set;
   
-  for (map< MusECore::Part*, set<MusECore::Part*> >::const_iterator it = param.begin(); it!=param.end(); it++)
+  for (map< const MusECore::Part*, set<const MusECore::Part*> >::const_iterator it = param.begin(); it!=param.end(); it++)
     if (_pl->index(it->first) != -1)
-      for (set<MusECore::Part*>::const_iterator it2=it->second.begin(); it2!=it->second.end(); it2++)
-        addPart(*it2);
+      for (set<const MusECore::Part*>::const_iterator it2=it->second.begin(); it2!=it->second.end(); it2++)
+        addPart(const_cast<MusECore::Part*>(*it2)); // FIXME make this const-correct!
 }
 
 } // namespace MusEGui
diff --git a/muse2/muse/midieditor.h b/muse2/muse/midieditor.h
index 900f06b1..39feeedf 100644
--- a/muse2/muse/midieditor.h
+++ b/muse2/muse/midieditor.h
@@ -76,7 +76,7 @@ class MidiEditor : public TopWin  {
       void genPartlist();
 
    private slots:
-      void addNewParts(const std::map< MusECore::Part*, std::set<MusECore::Part*> >&);
+      void addNewParts(const std::map< const MusECore::Part*, std::set<const MusECore::Part*> >&);
 
    public slots:
       void songChanged(MusECore::SongChangedFlags_t type);
diff --git a/muse2/muse/midievent.cpp b/muse2/muse/midievent.cpp
index 9fd47eaf..fb6517cd 100644
--- a/muse2/muse/midievent.cpp
+++ b/muse2/muse/midievent.cpp
@@ -41,11 +41,26 @@ MidiEventBase::MidiEventBase(EventType t)
       c = 0;
       }
 
+bool MidiEventBase::isSimilarTo(const EventBase& other_) const
+{
+	const MidiEventBase* other = dynamic_cast<const MidiEventBase*>(&other_);
+	if (other==NULL) // dynamic cast hsa failed: "other_" is not of type MidiEventBase.
+		return false;
+	
+	if ((a==other->a && b==other->b && c==other->c && edata.dataLen==other->edata.dataLen && this->PosLen::operator==(*other)) == false)
+		return false;
+	
+	if (edata.dataLen > 0)
+		return (memcmp(edata.data, other->edata.data, edata.dataLen) == 0);
+	else
+		return true; // no data equals no data.
+}
+
 //---------------------------------------------------------
 //   MidiEventBase::mid
 //---------------------------------------------------------
 
-EventBase* MidiEventBase::mid(unsigned b, unsigned e)
+EventBase* MidiEventBase::mid(unsigned b, unsigned e) const
       {
       if (tick() < b || tick() >= e)
             return 0;
diff --git a/muse2/muse/midievent.h b/muse2/muse/midievent.h
index a63fede2..dba2d727 100644
--- a/muse2/muse/midievent.h
+++ b/muse2/muse/midievent.h
@@ -36,11 +36,13 @@ class MidiEventBase : public EventBase {
       int a, b, c;                  // pitch, velo-on, velo-off
       EvData edata;
 
-      virtual EventBase* clone() { return new MidiEventBase(*this); }
+      virtual EventBase* clone() const { return new MidiEventBase(*this); }
 
    public:
       MidiEventBase(EventType t);
       virtual ~MidiEventBase() {}
+      
+      virtual bool isSimilarTo(const EventBase& other) const;
 
       virtual bool isNote() const                   { return type() == Note; }
       virtual bool isNoteOff() const;
@@ -71,7 +73,7 @@ class MidiEventBase : public EventBase {
       virtual void dump(int n = 0) const;
       virtual void read(Xml&);
       virtual void write(int, Xml&, const Pos& offset, bool forcePath = false) const;
-      virtual EventBase* mid(unsigned, unsigned);
+      virtual EventBase* mid(unsigned, unsigned) const;
       };
 
 } // namespace MusECore
diff --git a/muse2/muse/midiseq.cpp b/muse2/muse/midiseq.cpp
index 8d0427d8..f6463d59 100644
--- a/muse2/muse/midiseq.cpp
+++ b/muse2/muse/midiseq.cpp
@@ -81,11 +81,6 @@ void MidiSeq::processMsg(const ThreadMsg* m)
       {
       MusECore::AudioMsg* msg = (MusECore::AudioMsg*)m;
       switch(msg->id) {
-            // This does not appear to be used anymore. Was sent in Audio::process1,  DELETETHIS 5 ??
-            //  now Audio::processMidi is called directly. p4.0.15 Tim.
-            //case MusECore::MS_PROCESS:
-            //      audio->processMidi();
-            //      break;
             
             case MusECore::SEQM_SEEK:
                   processSeek();
@@ -104,52 +99,6 @@ void MidiSeq::processMsg(const ThreadMsg* m)
                   break;
                   
                   
-            // Moved into Song::processMsg p4.0.34  ...
-            case MusECore::SEQM_ADD_TRACK:
-                  MusEGlobal::song->insertTrack2(msg->track, msg->ival);
-                  updatePollFd();
-                  break;
-            case MusECore::SEQM_REMOVE_TRACK:
-                  MusEGlobal::song->cmdRemoveTrack(msg->track);
-                  updatePollFd();
-                  break;
-            //case MusECore::SEQM_CHANGE_TRACK: DELETETHIS 4
-            //      MusEGlobal::song->changeTrack((Track*)(msg->p1), (Track*)(msg->p2));
-            //      updatePollFd();
-            //      break;
-            case MusECore::SEQM_ADD_PART:
-                  MusEGlobal::song->cmdAddPart((Part*)msg->p1);
-                  break;
-            case MusECore::SEQM_REMOVE_PART:
-                  MusEGlobal::song->cmdRemovePart((Part*)msg->p1);
-                  break;
-            case MusECore::SEQM_CHANGE_PART:
-                  MusEGlobal::song->cmdChangePart((Part*)msg->p1, (Part*)msg->p2, msg->a, msg->b);
-                  break;
-                  
-                  
-            case MusECore::SEQM_SET_TRACK_OUT_CHAN:
-                  {
-                  MidiTrack* track = (MidiTrack*)(msg->p1);
-                  track->setOutChanAndUpdate(msg->a);
-                  }
-                  break;
-            case MusECore::SEQM_SET_TRACK_OUT_PORT:
-                  {
-                  MidiTrack* track = (MidiTrack*)(msg->p1);
-                  track->setOutPortAndUpdate(msg->a);
-                  }
-                  break;
-            case MusECore::SEQM_REMAP_PORT_DRUM_CTL_EVS:
-                    MusEGlobal::song->remapPortDrumCtrlEvents(msg->ival, msg->a, msg->b, msg->c);
-                  break;
-            case MusECore::SEQM_CHANGE_ALL_PORT_DRUM_CTL_EVS:      
-                    MusEGlobal::song->changeAllPortDrumCtrlEvents((bool)msg->a, (bool)msg->b);
-                  break;
-            case MusECore::SEQM_SET_MIDI_DEVICE:
-                  ((MidiPort*)(msg->p1))->setMidiDevice((MidiDevice*)(msg->p2));
-                  updatePollFd();
-                  break;
             case MusECore::SEQM_IDLE:
                   idle = msg->a;
                   break;
@@ -169,35 +118,12 @@ void MidiSeq::processStop()
   // TODO Try to move this into Audio::stopRolling(). 
   playStateExt = false; // not playing
   
-  //
-  //    clear Alsa midi device notes and stop stuck notes
-  //
+  // clear Alsa midi device notes and stop stuck notes
   for(iMidiDevice id = MusEGlobal::midiDevices.begin(); id != MusEGlobal::midiDevices.end(); ++id) 
-  {
-    //MidiDevice* md = *id; DELETETHIS 3
-    // Only ALSA devices are handled by this thread.
-    //if((*id)->deviceType() == MidiDevice::ALSA_MIDI)      
       (*id)->handleStop();  
-    /* DELETETHIS 14
-    if (md->midiPort() == -1)
-          continue;
-    MPEventList* pel = md->playEvents();
-    MPEventList* sel = md->stuckNotes();
-    pel->clear();
-    for(iMPEvent i = sel->begin(); i != sel->end(); ++i) 
-    {
-      MidiPlayEvent ev = *i;
-      ev.setTime(0);
-      pel->add(ev);
-    }
-    sel->clear();
-    //md->setNextPlayEvent(pel->begin());  // Removed p4.0.15
-    */
-  }
 }
 #endif
 
-#if 1   //DELETETHIS #if and #endif
 //---------------------------------------------------------
 //   processSeek
 //---------------------------------------------------------
@@ -209,62 +135,8 @@ void MidiSeq::processSeek()
   //---------------------------------------------------
 
   for (iMidiDevice i = MusEGlobal::midiDevices.begin(); i != MusEGlobal::midiDevices.end(); ++i) 
-  {
-    //MidiDevice* md = *i; DELETETHIS 3
-    // Only ALSA devices are handled by this thread.
-    //if((*i)->deviceType() == MidiDevice::ALSA_MIDI)      
       (*i)->handleSeek();  
-    /* DELETETHIS 47
-    int port = md->midiPort();
-    if (port == -1)
-          continue;
-    MidiPort* mp = &MusEGlobal::midiPorts[port];
-    MidiCtrlValListList* cll = mp->controller();
-
-    MPEventList* el = md->playEvents();
-
-    if (MusEGlobal::audio->isPlaying()) 
-    {
-      // stop all notes
-      el->clear();
-      MPEventList* sel = dev->stuckNotes();
-      for (iMPEvent i = sel->begin(); i != sel->end(); ++i) 
-      {
-            MidiPlayEvent ev = *i;
-            ev.setTime(0);
-            el->add(ev);
-      }
-      sel->clear();
-    }
-    //else
-      // Removed p4.0.15 Device now leaves beginning pointing at next event,
-      //  immediately after playing some notes.  
-      // NOTE: This removal needs testing. I'm not sure about this.
-      //el->erase(el->begin(), dev->nextPlayEvent());  
-    
-    for (iMidiCtrlValList ivl = cll->begin(); ivl != cll->end(); ++ivl) 
-    {
-      MidiCtrlValList* vl = ivl->second;
-      //int val = vl->value(pos);
-      //if (val != CTRL_VAL_UNKNOWN) {
-      //      int channel = ivl->first >> 24;
-      //      el->add(MidiPlayEvent(0, port, channel, ME_CONTROLLER, vl->num(), val));
-      //      }
-      iMidiCtrlVal imcv = vl->iValue(pos);
-      if(imcv != vl->end()) 
-      {
-        Part* p = imcv->second.part;
-        unsigned t = (unsigned)imcv->first;
-        // Do not add values that are outside of the part.
-        if(p && t >= p->tick() && t < (p->tick() + p->lenTick()) )
-          el->add(MidiPlayEvent(0, port, ivl->first >> 24, ME_CONTROLLER, vl->num(), imcv->second.val));
-      }
-    }
-    //dev->setNextPlayEvent(el->begin());    // Removed p4.0.15
-    */
-  }
 }
-#endif
 
 //---------------------------------------------------------
 //   MidiSeq
@@ -353,22 +225,6 @@ signed int MidiSeq::selectTimer()
 
 void MidiSeq::threadStart(void*)
       {
-      // Removed by Tim. p3.3.17 DELETETHIS 13
-      /*
-      struct sched_param rt_param;
-      memset(&rt_param, 0, sizeof(rt_param));
-      int prio_min = sched_get_priority_min(SCHED_FIFO);
-      int prio_max = sched_get_priority_max(SCHED_FIFO);
-
-      if (prio < prio_min) prio = prio_min;
-      else if (prio > prio_max) prio = prio_max;
-
-      rt_param.sched_priority = prio;
-      int rv = pthread_setschedparam(pthread_self(), SCHED_FIFO, &rt_param);
-      if (rv != 0)
-            perror("set realtime scheduler");
-      */
-
       int policy;
       if ((policy = sched_getscheduler (0)) < 0) {
             printf("Cannot get current client scheduler: %s\n", strerror(errno));
@@ -398,19 +254,6 @@ static void midiRead(void*, void* d)
       dev->processInput();
       }
 
-// DELETETHIS 12
-//---------------------------------------------------------
-//   synthIRead
-//---------------------------------------------------------
-
-#if 0
-static void synthIRead(void*, void* d)
-      {
-      SynthI* syn = (SynthI*) d;
-      syn->processInput();
-      }
-#endif
-
 //---------------------------------------------------------
 //   midiWrite
 //---------------------------------------------------------
@@ -590,42 +433,6 @@ void MidiSeq::setSyncRecFilterPreset(MidiSyncInfo::SyncRecFilterPresetType type)
 }
 
 
-//---------------------------------------------------------
-//   processMidiClock
-//---------------------------------------------------------
-
-void MidiSeq::processMidiClock()
-      {
-      // DELETETHIS 30, maybe remove entire function?
-//      if (genMCSync) {
-//            MusEGlobal::midiPorts[txSyncPort].sendClock();
-//      }
-
-/*      if (state == START_PLAY) {
-            // start play on sync
-            state      = PLAY;
-            _midiTick  = playTickPos;
-            midiClock  = playTickPos;
-
-            int bar, beat, tick;
-            sigmap.tickValues(_midiTick, &bar, &beat, &tick);
-            midiClick      = sigmap.bar2tick(bar, beat+1, 0);
-
-            double cpos    = MusEGlobal::tempomap.tick2time(playTickPos);
-            samplePosStart = samplePos - lrint(cpos * MusEGlobal::sampleRate);
-            rtcTickStart   = rtcTick - lrint(cpos * realRtcTicks);
-
-            endSlice       = playTickPos;
-            recTick        = playTickPos;
-            lastTickPos    = playTickPos;
-
-            tempoSN = MusEGlobal::tempomap.tempoSN();
-
-            startRecordPos.setPosTick(playTickPos);
-            }
-*/
-//      midiClock += MusEGlobal::config.division/24;
-      }
 
 //---------------------------------------------------------
 //   midiTick
@@ -698,126 +505,18 @@ void MidiSeq::processTimerTick()
                       mp->sendClock();
                     }
                     
-                    // DELETETHIS 35 ??
-                    /*
-                    for(iMidiDevice imd = MusEGlobal::midiDevices.begin(); imd != MusEGlobal::midiDevices.end(); ++imd) 
-                    {
-                      MidiDevice* dev = *imd;
-                      
-                      if(!dev->syncInfo().MCOut())
-                        continue;
-                        
-                      // Shall we check open flags?
-                      //if(!(dev->rwFlags() & 0x1) || !(dev->openFlags() & 1))
-                      //if(!(dev->openFlags() & 1))
-                      //  continue;
-        
-                      int port = dev->midiPort();
-                      // Without this -1 check, interesting sync things can be done by the user without ever
-                      //  assigning any devices to ports ! 
-                      //if(port < 0 || port > MIDI_PORTS)
-                      if(port < -1 || port > MIDI_PORTS)
-                        continue;
-                        
-                      if(port == -1)
-                      // Send straight to the device... Copied from MidiPort.
-                      {
-                        MidiPlayEvent event(0, 0, 0, ME_CLOCK, 0, 0);
-                        dev->putEvent(event);
-                      }  
-                      else
-                        // Go through the port...
-                        MusEGlobal::midiPorts[port].sendClock();
-                    }
-                    */
-                    
                     if(MusEGlobal::debugMsg && used && perr > 1)
                       printf("Dropped %d midi out clock(s). curTick:%d midiClock:%d div:%d\n", perr, curTick, midiClock, div);
-                  //} DELETETHIS and maybe the below ???
-                    
-                  // Increment as if we had caught the timer exactly on the mark, even if the timer
-                  //  has passed beyond the mark, or even beyond 2 * div.
-                  // If we missed some chances to send clock, resume the count where it would have been, 
-                  //  had we not missed chances.
-                  // We can't do anything about missed chances except send right away, and make up
-                  //  for gained time by losing time in the next count...
-                  // In other words, use equalization periods to counter gained/lost time, so that
-                  //  ultimately, over time, the receiver remains in phase, despite any short dropouts / phase glitches.
-                  // (midiClock only increments by div units).
-                  //
-                  // Tested: With midi thread set to high priority, very few clock dropouts ocurred (P4 1.6Ghz).
-                  // But target device tick drifts out of phase with muse tick slowly over time, say 20 bars or so.
-                  // May need more tweaking, possibly use round with/instead of lrint (above), and/or
-                  //  do not use equalization periods - set midiClock to fractions of div.
-                  // Tested: With RTC resolution at 1024, stability was actually better than with 8192!
-                  // It stayed in sync more than 64 bars...
-                  //
-                  //
+
                   // Using equalization periods...
                   midiClock += (perr * div);
-                  //midiClock += perr; DELETETHIS
-                  //
-                  // No equalization periods... TODO: or DELETETHIS?
-                  //midiClock += (perr * div);
                }
             }
 
       // play all events upto curFrame
-      for (iMidiDevice id = MusEGlobal::midiDevices.begin(); id != MusEGlobal::midiDevices.end(); ++id) {
-            //MidiDevice* md = *id; DELETETHIS 10
-            // Is it a Jack midi device? They are iterated in Audio::processMidi. p3.3.36 
-            //MidiJackDevice* mjd = dynamic_cast<MidiJackDevice*>(md);
-            //if(mjd)
-            //if(md->deviceType() == MidiDevice::JACK_MIDI)
-            //  continue;
-            //if(md->isSynti())      // syntis are handled by audio thread
-            //      continue;
-            // Only ALSA midi devices are handled by this thread.
+      for (iMidiDevice id = MusEGlobal::midiDevices.begin(); id != MusEGlobal::midiDevices.end(); ++id)
             if((*id)->deviceType() == MidiDevice::ALSA_MIDI)
               (*id)->processMidi();
-            
-            // Moved into MidiAlsaDevice.      p4.0.34 DELETETHIS 40
-            /*
-            int port = md->midiPort();
-            MidiPort* mp = port != -1 ? &MusEGlobal::midiPorts[port] : 0;
-            MPEventList* el = md->playEvents();
-            if (el->empty())
-                  continue;
-            
-            ///iMPEvent i = md->nextPlayEvent();
-            iMPEvent i = el->begin();            // p4.0.15 Tim.
-            
-            for (; i != el->end(); ++i) {
-                  // p3.3.25
-                  // If syncing to external midi sync, we cannot use the tempo map.
-                  // Therefore we cannot get sub-tick resolution. Just use ticks instead of frames.
-                  //if (i->time() > curFrame) {
-                  if (i->time() > (extsync ? tickpos : curFrame)) {
-                        //printf("  curT %d  frame %d\n", i->time(), curFrame);
-                        break; // skip this event
-                        }
-
-                  if (mp) {
-                        if (mp->sendEvent(*i))
-                              break;
-                        }
-                  else {
-                        if (md->putEvent(*i))
-                              break;
-                        }
-                  }
-            ///md->setNextPlayEvent(i);
-            // p4.0.15 We are done with these events. Let us erase them here instead of Audio::processMidi.
-            // That way we can simply set the next play event to the beginning.
-            // This also allows other events to be inserted without the problems caused by the next play event 
-            //  being at the 'end' iterator and not being *easily* set to some new place beginning of the newer insertions. 
-            // The way that MPEventList sorts made it difficult to predict where the iterator of the first newly inserted items was.
-            // The erasure in Audio::processMidi was missing some events because of that.
-            el->erase(el->begin(), i);
-            //md->setNextPlayEvent(el->begin());  // Removed p4.0.15
-            */
-            
-            }
       }
 
 //---------------------------------------------------------
diff --git a/muse2/muse/midiseq.h b/muse2/muse/midiseq.h
index 08adcdce..4a7fd829 100644
--- a/muse2/muse/midiseq.h
+++ b/muse2/muse/midiseq.h
@@ -78,7 +78,6 @@ class MidiSeq : public Thread {
       void processTimerTick();
       void processSeek();
       void processStop();
-      void processMidiClock();
       virtual void processMsg(const ThreadMsg*);
       void updatePollFd();
 
diff --git a/muse2/muse/miditransform.cpp b/muse2/muse/miditransform.cpp
index f9289dcc..723e067b 100644
--- a/muse2/muse/miditransform.cpp
+++ b/muse2/muse/miditransform.cpp
@@ -41,6 +41,9 @@
 #include "gconfig.h"
 #include "midictrl.h"
 
+using MusECore::Undo;
+using MusECore::UndoOp;
+
 namespace MusECore {
 
 //
@@ -484,8 +487,7 @@ void MidiTransformerDialog::accept()
 //    subfunction of processEvent()
 //---------------------------------------------------------
 
-void MidiTransformerDialog::transformEvent(MusECore::Event& event, MusECore::MidiPart* part,
-  MusECore::MidiPart* newPart)
+void MidiTransformerDialog::transformEvent(MusECore::Event& event, MusECore::MidiPart* part, MusECore::MidiPart* newPart, MusECore::Undo& operations)
       {
       MusECore::MidiTransformation* cmt = data->cmt;
       MusECore::Event newEvent = event.clone();
@@ -676,33 +678,16 @@ void MidiTransformerDialog::transformEvent(MusECore::Event& event, MusECore::Mid
             pos = 0;
       newEvent.setTick(pos);
 
-      MusECore::Event dummy;
       switch(data->cmt->funcOp) {
             case MusECore::Transform:
-                  // Indicate do clone parts. 
-                  removePortCtrlEvents(event, part, true);
-                  MusEGlobal::song->changeEvent(event, newEvent, part);
-                  // Indicate do clone parts. 
-                  addPortCtrlEvents(newEvent, part, true);
-                  // Indicate do port controller values and clone parts. 
-                  MusEGlobal::song->addUndo(MusECore::UndoOp(MusECore::UndoOp::ModifyEvent, newEvent, event, part, true, true));
-                  MusEGlobal::song->addUpdateFlags(SC_EVENT_MODIFIED);
+                  operations.push_back(UndoOp(UndoOp::ModifyEvent, newEvent, event, part, true, true));
                   break;
             case MusECore::Insert:
                   // Indicate do port controller values and clone parts. 
-                  MusEGlobal::song->addUndo(MusECore::UndoOp(MusECore::UndoOp::AddEvent, dummy, newEvent, part, true, true));
-                  MusEGlobal::song->addEvent(newEvent, part);
-                  // Indicate do clone parts. 
-                  addPortCtrlEvents(newEvent, part, true);
-                  MusEGlobal::song->addUpdateFlags(SC_EVENT_INSERTED);
+                  operations.push_back(UndoOp(UndoOp::AddEvent, newEvent, part, true, true));
                   break;
             case MusECore::Extract:
-                  // Indicate do port controller values and clone parts. 
-                  MusEGlobal::song->addUndo(MusECore::UndoOp(MusECore::UndoOp::DeleteEvent, dummy, event, part, true, true));
-                  // Indicate do clone parts. 
-                  removePortCtrlEvents(event, part, true);
-                  MusEGlobal::song->deleteEvent(event, part);
-                  MusEGlobal::song->addUpdateFlags(SC_EVENT_REMOVED);
+                  operations.push_back(UndoOp(UndoOp::DeleteEvent, event, part, true, true));
             case MusECore::Copy:
                   newPart->addEvent(newEvent);
                   break;
@@ -715,7 +700,7 @@ void MidiTransformerDialog::transformEvent(MusECore::Event& event, MusECore::Mid
 //   processEvent
 //---------------------------------------------------------
 
-void MidiTransformerDialog::processEvent(MusECore::Event& event, MusECore::MidiPart* part, MusECore::MidiPart* newPart)
+void MidiTransformerDialog::processEvent(MusECore::Event& event, MusECore::MidiPart* part, MusECore::MidiPart* newPart, MusECore::Undo& operations)
       {
       switch(data->cmt->funcOp) {
             case MusECore::Select:
@@ -725,35 +710,22 @@ void MidiTransformerDialog::processEvent(MusECore::Event& event, MusECore::MidiP
                   int tick = event.tick();
                   int rt = AL::sigmap.raster(tick, data->cmt->quantVal) - tick;
                   if (tick != rt) {
-                        // Indicate do clone parts. 
-                        removePortCtrlEvents(event, part, true);
                         MusECore::Event newEvent = event.clone();
                         newEvent.setTick(rt);
-                        MusEGlobal::song->changeEvent(event, newEvent, part);
-                        // Indicate do clone parts. 
-                        addPortCtrlEvents(newEvent, part, true);
-                        // Indicate do port controller values and clone parts. 
-                        MusEGlobal::song->addUndo(MusECore::UndoOp(MusECore::UndoOp::ModifyEvent, newEvent, event, part, true, true));
-                        MusEGlobal::song->addUpdateFlags(SC_EVENT_MODIFIED);
+						operations.push_back(UndoOp(UndoOp::ModifyEvent,newEvent,event,part,true,true));
                         }
                   }
                   break;
             case MusECore::Delete:
                   {
-                  MusECore::Event ev;
-                  // Indicate do port controller values and clone parts. 
-                  MusEGlobal::song->addUndo(MusECore::UndoOp(MusECore::UndoOp::DeleteEvent, ev, event, part, true, true));
-                  // Indicate do clone parts. 
-                  removePortCtrlEvents(event, part, true);
-                  MusEGlobal::song->deleteEvent(event, part);
-                  MusEGlobal::song->addUpdateFlags(SC_EVENT_REMOVED);
+                  operations.push_back(UndoOp(UndoOp::DeleteEvent, event, part, true, true));
                   }
                   break;
             case MusECore::Transform:
             case MusECore::Insert:
             case MusECore::Copy:
             case MusECore::Extract:
-                  transformEvent(event, part, newPart);
+                  transformEvent(event, part, newPart, operations);
                   break;
             }
       }
@@ -764,7 +736,7 @@ void MidiTransformerDialog::processEvent(MusECore::Event& event, MusECore::MidiP
 //    return true if event is selected
 //---------------------------------------------------------
 
-bool MidiTransformerDialog::isSelected(MusECore::Event& event, MusECore::MidiPart*)
+bool MidiTransformerDialog::isSelected(const MusECore::Event& event)
       {
       MusECore::MidiTransformation* cmt = data->cmt;
 
@@ -927,13 +899,13 @@ bool MidiTransformerDialog::isSelected(MusECore::Event& event, MusECore::MidiPar
 void MidiTransformerDialog::apply()
       {
       MusECore::SongChangedFlags_t flags = 0;
-      MusEGlobal::song->startUndo();
-      MusEGlobal::audio->msgIdle(true);
+	  
+	  Undo operations;
       bool copyExtract = (data->cmt->funcOp == MusECore::Copy)
                          || (data->cmt->funcOp == MusECore::Extract);
 
-      std::vector< MusECore::EventList* > doneList;
-      typedef std::vector< MusECore::EventList* >::iterator iDoneList;
+      QSet< int > doneList;
+      typedef std::set< int >::iterator iDoneList;
       iDoneList idl;
       
       MusECore::MidiTrackList* tracks = MusEGlobal::song->midis();
@@ -947,21 +919,18 @@ void MidiTransformerDialog::apply()
                   // check wether we must generate a new track
                   for (MusECore::iPart p = pl->begin(); p != pl->end(); ++p) {
                         MusECore::MidiPart* part = (MusECore::MidiPart *) p->second;
-                        MusECore::EventList* el = part->events();
+                        const MusECore::EventList& el = part->events();
                         // Check if the event list has already been done. Skip repeated clones.
-                        for(idl = doneList.begin(); idl != doneList.end(); ++idl)
-                          if(*idl == el)
-                            break;
-                        if(idl != doneList.end())
-                          break;
-                        doneList.push_back(el);
+                        if (doneList.contains(part->clonemaster_sn()))
+                             continue;
+                        doneList.insert(part->clonemaster_sn());
                         
-                        for (MusECore::iEvent i = el->begin(); i != el->end(); ++i) {
-                              MusECore::Event event = i->second;
+                        for (MusECore::ciEvent i = el.begin(); i != el.end(); ++i) {
+                              const MusECore::Event& event = i->second;
                               unsigned tick = event.tick();
                               if (data->cmt->insideLoop && (tick < MusEGlobal::song->lpos() || tick >= MusEGlobal::song->rpos()))
                                     continue;
-                              if (isSelected(event, part)) {
+                              if (isSelected(event)) {
                                     newTrack = new MusECore::MidiTrack();
                                     tl.push_back(newTrack);
                                     break;
@@ -975,82 +944,56 @@ void MidiTransformerDialog::apply()
             for (MusECore::iPart p = pl->begin(); p != pl->end(); ++p) {
                   MusECore::MidiPart* part = (MusECore::MidiPart *) p->second;
                   MusECore::MidiPart* newPart = 0;
-                  MusECore::EventList* el = part->events();
+                  const MusECore::EventList& el = part->events();
                   // Check if the event list has already been done. Skip repeated clones.
-                  for(idl = doneList.begin(); idl != doneList.end(); ++idl)
-                    if(*idl == el)
-                      break;
-                  if(idl != doneList.end())
-                    break;
-                  doneList.push_back(el);
+                  if (doneList.contains(part->clonemaster_sn()))
+                      continue;
+                  doneList.insert(part->clonemaster_sn());
                   
                   if (copyExtract) {
                         // check wether we must generate a new part
-                        for (MusECore::iEvent i = el->begin(); i != el->end(); ++i) {
-                              MusECore::Event event = i->second;
+                        for (MusECore::ciEvent i = el.begin(); i != el.end(); ++i) {
+                              const MusECore::Event& event = i->second;
                               unsigned tick = event.tick();
                               if (data->cmt->insideLoop && (tick < MusEGlobal::song->lpos() || tick >= MusEGlobal::song->rpos()))
                                     continue;
-                              if (isSelected(event, part)) {
+                              if (isSelected(event)) {
                                     newPart = new MusECore::MidiPart(newTrack);
                                     newPart->setName(part->name());
                                     newPart->setColorIndex(part->colorIndex());
                                     newPart->setTick(part->tick());
                                     newPart->setLenTick(part->lenTick());
-                                    MusEGlobal::song->addPart(newPart);
+                                    operations.push_back(UndoOp(UndoOp::AddPart,newPart));
                                     flags |= SC_PART_INSERTED;
                                     break;
                                     }
                               }
                         }
                   MusECore::EventList pel;
-                  for (MusECore::iEvent i = el->begin(); i != el->end(); ++i) {
-                        MusECore::Event event = i->second;
+                  for (MusECore::ciEvent i = el.begin(); i != el.end(); ++i) {
+                        const MusECore::Event& event = i->second;
                         unsigned tick = event.tick();
                         if (data->cmt->insideLoop && (tick < MusEGlobal::song->lpos() || tick >= MusEGlobal::song->rpos()))
                               continue;
-                        int flag = isSelected(event, part);
+                        int flag = isSelected(event);
                         if (data->cmt->funcOp == MusECore::Select)
-                              event.setSelected(flag);
+                              operations.push_back(UndoOp(UndoOp::SelectEvent, event,flag, event.selected()));
                         else if (flag)
-                              pel.add(event);
+                              pel.add(const_cast<MusECore::Event&>(event)); // ough, FIXME, what an ugly hack.
                         }
                   for (MusECore::iEvent i = pel.begin(); i != pel.end(); ++i) {
                         MusECore::Event event = i->second;
-                        processEvent(event, part, newPart);
+                        processEvent(event, part, newPart, operations);
                         }
                   }
             }
       if (!tl.empty()) {
             flags |= SC_TRACK_INSERTED;
-            for (MusECore::iTrack t = tl.begin(); t != tl.end(); ++t) {
-                  MusEGlobal::song->insertTrack0(*t, -1);
-                  }
-            }
+            for (MusECore::iTrack t = tl.begin(); t != tl.end(); ++t)
+                  operations.push_back(UndoOp(UndoOp::AddTrack, -1, *t));
+      }
 
-      switch(data->cmt->funcOp) {
-            case MusECore::Select:
-                  flags |= SC_SELECTION;
-                  break;
-            case MusECore::Quantize:
-                  flags |= SC_EVENT_MODIFIED;
-                  break;
-            case MusECore::Delete:
-                  flags |= SC_EVENT_REMOVED;
-                  break;
-            case MusECore::Transform:
-                  flags |= SC_EVENT_MODIFIED;
-                  break;
-            case MusECore::Insert:
-                  flags |= SC_EVENT_INSERTED;
-                  break;
-            case MusECore::Copy:
-                  flags |= SC_EVENT_INSERTED;
-            case MusECore::Extract:
-                  break;
-            }
-      MusEGlobal::audio->msgIdle(false);
-      MusEGlobal::song->endUndo(flags);
+      MusEGlobal::song->applyOperationGroup(operations);
       }
 
 //---------------------------------------------------------
@@ -1721,9 +1664,9 @@ void MidiTransformerDialog::insideLoopChanged(bool val)
 
 
 /*!
-    \fn MidiTransformerDialog::typesMatch(MusECore::MidiEvent e, unsigned t)
+    \fn MidiTransformerDialog::typesMatch(const MusECore::MidiEvent e, unsigned t)
  */
-bool MidiTransformerDialog::typesMatch(MusECore::Event& e, unsigned selType)
+bool MidiTransformerDialog::typesMatch(const MusECore::Event& e, unsigned selType)
       {
       bool matched = false;
       switch (selType)
diff --git a/muse2/muse/miditransform.h b/muse2/muse/miditransform.h
index e8022277..5ff78357 100644
--- a/muse2/muse/miditransform.h
+++ b/muse2/muse/miditransform.h
@@ -32,6 +32,7 @@ class QDialog;
 
 namespace MusECore {
 
+class Undo;
 class Event;
 class MidiPart;
 class MidiTransformation;
@@ -84,10 +85,10 @@ class MidiTransformerDialog : public QDialog, public Ui::MidiTransformDialogBase
 
       virtual void accept();
       void setValOp(QWidget* a, QWidget* b, MusECore::ValOp op);
-      void processEvent(MusECore::Event&, MusECore::MidiPart*, MusECore::MidiPart*);
-      bool isSelected(MusECore::Event&, MusECore::MidiPart*);
-      void transformEvent(MusECore::Event&, MusECore::MidiPart*, MusECore::MidiPart*);
-      bool typesMatch(MusECore::Event& e, unsigned selType);
+      void processEvent(MusECore::Event&, MusECore::MidiPart*, MusECore::MidiPart*, MusECore::Undo& operations);
+      bool isSelected(const MusECore::Event&);
+      void transformEvent(MusECore::Event&, MusECore::MidiPart*, MusECore::MidiPart*, MusECore::Undo& operations);
+      bool typesMatch(const MusECore::Event& e, unsigned selType);
       
       void updatePresetList();
 
diff --git a/muse2/muse/mixer/strip.cpp b/muse2/muse/mixer/strip.cpp
index 06ee9443..cf4be792 100644
--- a/muse2/muse/mixer/strip.cpp
+++ b/muse2/muse/mixer/strip.cpp
@@ -42,6 +42,9 @@
 #include "meter.h"
 #include "utils.h"
 #include "icons.h"
+#include "undo.h"
+
+using MusECore::UndoOp;
 
 namespace MusEGui {
 
@@ -340,8 +343,7 @@ void Strip::mousePressEvent(QMouseEvent* ev)
       QFrame::mousePressEvent(ev);
       return;
     }
-    MusEGlobal::song->removeTrack0(track);
-    MusEGlobal::audio->msgUpdateSoloStates();
+    MusEGlobal::song->applyOperation(UndoOp(UndoOp::DeleteTrack, MusEGlobal::song->tracks()->index(track), track));
     ev->accept();
     return;
   }
diff --git a/muse2/muse/part.cpp b/muse2/muse/part.cpp
index 5f3aa8ee..1d246c50 100644
--- a/muse2/muse/part.cpp
+++ b/muse2/muse/part.cpp
@@ -22,6 +22,7 @@
 //
 //=========================================================
 
+#include <assert.h>
 #include <stdio.h>
 #include <cmath>
 
@@ -39,316 +40,97 @@ namespace MusECore {
 
 int Part::snGen=0;
 
-//---------------------------------------------------------
-//   unchainClone
-//---------------------------------------------------------
 
-void unchainClone(Part* p)
+void Part::unchainClone()
 {
-  chainCheckErr(p);
+  chainCheckErr(this); // FIXME proper assert!
   
-  // Unchain the part.
-  p->prevClone()->setNextClone(p->nextClone());
-  p->nextClone()->setPrevClone(p->prevClone());
+  if (_backupClone) printf("THIS SHOULD NEVER HAPPEN: Part::unchainClone() called, but _backupClone was non-NULL\n");
   
-  // Isolate the part.
-  p->setPrevClone(p);
-  p->setNextClone(p);
-}
-
-//---------------------------------------------------------
-//   chainClone
-//   The quick way - if part to chain to is known...
-//---------------------------------------------------------
-
-void chainClone(Part* p1, Part* p2)
-{
-  chainCheckErr(p1);
+  _backupClone=_prevClone;
   
-  // Make sure the part to be chained is unchained first.
-  p2->prevClone()->setNextClone(p2->nextClone());
-  p2->nextClone()->setPrevClone(p2->prevClone());
+  // Unchain the part.
+  _prevClone->_nextClone = _nextClone;
+  _nextClone->_prevClone = _prevClone;
   
-  // Link the part to be chained.
-  p2->setPrevClone(p1);
-  p2->setNextClone(p1->nextClone());
+  // Isolate the part.
+  _prevClone = this;
+  _nextClone = this;
   
-  // Re-link the existing part.
-  p1->nextClone()->setPrevClone(p2);
-  p1->setNextClone(p2);
+  _clonemaster_sn = this->_sn;
 }
 
-//---------------------------------------------------------
-//   chainCloneInternal
-//   No error check, so it can be called by replaceClone()
-//---------------------------------------------------------
-
-void chainCloneInternal(Part* p)
+void Part::chainClone(Part* p)
 {
-  Track* t = p->track();
-  Part* p1 = 0;
+  // FIXME assertion
+  assert(p);
   
-  // Look for a part with the same event list, that we can chain to.
-  // It's faster if track type is known...
-  
-  if(!t || (t && t->isMidiTrack()))
+  if (! (_prevClone==this && _nextClone==this)) // the part is still part of a clone chain!
   {
-    MidiTrack* mt = 0;
-    MidiTrackList* mtl = MusEGlobal::song->midis();
-    for(ciMidiTrack imt = mtl->begin(); imt != mtl->end(); ++imt)
-    {
-      mt = *imt;
-      const PartList* pl = mt->cparts();
-      for(ciPart ip = pl->begin(); ip != pl->end(); ++ip)
-      {
-        if(ip->second != p && ip->second->cevents() == p->cevents())
-        {
-          p1 = ip->second;
-          break;
-        }
-      }
-      // If a suitable part was found on a different track, we're done. We will chain to it.
-      // Otherwise keep looking for parts on another track. If no others found, then we
-      //  chain to any suitable part which was found on the same given track t.
-      if(p1 && mt != t)
-        break;
-    }
-  }  
-  if((!p1 && !t) || (t && t->type() == Track::WAVE))
-  {
-    MusECore::WaveTrack* wt = 0;
-    MusECore::WaveTrackList* wtl = MusEGlobal::song->waves();
-    for(MusECore::ciWaveTrack iwt = wtl->begin(); iwt != wtl->end(); ++iwt)
-    {
-      wt = *iwt;
-      const PartList* pl = wt->cparts();
-      for(ciPart ip = pl->begin(); ip != pl->end(); ++ip)
-      {
-        if(ip->second != p && ip->second->cevents() == p->cevents())
-        {
-          p1 = ip->second;
-          break;
-        }
-      }
-      if(p1 && wt != t)
-        break;
-    }
+    printf("ERROR: THIS SHOULD NEVER HAPPEN: Part::chainClone() called, but part is already chained! I'll unchain for now, but better fix that!\n");
+    this->unchainClone();
   }
+
+  // Make our links to the chain
+  this->_prevClone = p;
+  this->_nextClone = p->_nextClone;
   
-  // No part found with same event list? Done.
-  if(!p1)
-    return;
-    
-  // Make sure the part to be chained is unchained first.
-  p->prevClone()->setNextClone(p->nextClone());
-  p->nextClone()->setPrevClone(p->prevClone());
+  // Make the chain's links to us
+  this->_nextClone->_prevClone = this;
+  p->_nextClone = this;
   
-  // Link the part to be chained.
-  p->setPrevClone(p1);
-  p->setNextClone(p1->nextClone());
+  // we only chain clones. we must trust in the GUI thread that the eventlist is consistent.
   
-  // Re-link the existing part.
-  p1->nextClone()->setPrevClone(p);
-  p1->setNextClone(p);
+  this->_clonemaster_sn = p->_sn;
 }
 
-//---------------------------------------------------------
-//   chainClone
-//   The slow way - if part to chain to is not known...
-//---------------------------------------------------------
-
-void chainClone(Part* p)
+void Part::rechainClone()
 {
-  chainCheckErr(p);
-  chainCloneInternal(p);
+    if(_backupClone)
+    {
+        this->chainClone(_backupClone);
+        _backupClone = NULL;
+    }
 }
 
-//---------------------------------------------------------
-//   replaceClone
-//---------------------------------------------------------
+bool Part::isCloneOf(const Part* other) const
+{
+	return this->_clonemaster_sn == other->_clonemaster_sn;
+}
 
-// this replaces p1 by p2. p1 is isolated, and p2 takes its place instead.
-void replaceClone(Part* p1, Part* p2)
+int Part::nClones() const
 {
-  chainCheckErr(p1);
-  
-  // Make sure the replacement part is unchained first.
-  p2->prevClone()->setNextClone(p2->nextClone());
-  p2->nextClone()->setPrevClone(p2->prevClone());
-  
-  // If the two parts share the same event list, then this MUST 
-  //  be a straight forward replacement operation. Continue on.
-  // If not, and either part has more than one ref count, then do this...
-  if(p1->cevents() != p2->cevents())
-  {
-    bool ret = false;
-    // If the part to be replaced is a single uncloned part,  [DELETETHIS 4 this seems outdated=wrong to me]
-    //  and the replacement part is not, then this operation
-    //  MUST be an undo of a de-cloning of a cloned part.  
-    //if(p1->cevents()->refCount() <= 1 && p2->cevents()->refCount() > 1)
-    if(p2->cevents()->refCount() > 1)
-    {  
-      // Chain the replacement part. We don't know the chain it came from,
-      //  so we use the slow method.
-      chainCloneInternal(p2);
-      //return; DELETETHIS
-      ret = true;
-    }
-    
-    // If the replacement part is a single uncloned part,    DELETETHIS same as above
-    //  and the part to be replaced is not, then this operation
-    //  MUST be a de-cloning of a cloned part.  
-    //if(p1->cevents()->refCount() > 1 && p2->cevents()->refCount() <= 1)
-    if(p1->cevents()->refCount() > 1)
-    {  
-      // Unchain the part to be replaced.
-      p1->prevClone()->setNextClone(p1->nextClone());
-      p1->nextClone()->setPrevClone(p1->prevClone());
-      // Isolate the part.
-      p1->setPrevClone(p1);
-      p1->setNextClone(p1);
-      ret = true;
-    }
-    
-    // Was the operation handled?
-    if(ret)
-      return;
-    // Note that two parts here with different event lists, each with more than one
-    //  reference count, would be an error. It's not done anywhere in muse. But just 
-    //  to be sure, four lines above were changed to allow that condition.
-    // If each of the two different event lists, has only one ref count, we
-    //  handle it like a regular replacement, below...
-  }
-  
-  // If the part to be replaced is a clone not a single lone part, re-link its neighbours to the replacement part...
-  if(p1->prevClone() != p1)
-  {
-    p1->prevClone()->setNextClone(p2);
-    p2->setPrevClone(p1->prevClone());
-  }
-  else  
-    p2->setPrevClone(p2);
-  
-  if(p1->nextClone() != p1)
-  {
-    p1->nextClone()->setPrevClone(p2);
-    p2->setNextClone(p1->nextClone());
-  }
-  else
-    p2->setNextClone(p2);
-  
-  // Isolate the replaced part.
-  p1->setNextClone(p1);
-  p1->setPrevClone(p1);
+	int n=1;
+	
+	for(const Part* it = this->_nextClone; it!=this; it=it->_nextClone)
+		n++;
+	
+	return n;
 }
 
+
+// FIXME FINDMICHJETZT TODO: weg damit!
+
 //---------------------------------------------------------
 //   unchainTrackParts
 //---------------------------------------------------------
 
-void unchainTrackParts(Track* t, bool decRefCount)
+void unchainTrackParts(Track* t)
 {
   PartList* pl = t->parts();
   for(iPart ip = pl->begin(); ip != pl->end(); ++ip)
-  {
-    Part* p = ip->second;
-    chainCheckErr(p);
-    
-    // Do we want to decrease the reference count?
-    if(decRefCount)
-      p->events()->incARef(-1);
-      
-    // Unchain the part.
-    p->prevClone()->setNextClone(p->nextClone());
-    p->nextClone()->setPrevClone(p->prevClone());
-    
-    // Isolate the part.
-    p->setPrevClone(p);
-    p->setNextClone(p);
-  }
+    ip->second->unchainClone();
 }
 
 //---------------------------------------------------------
 //   chainTrackParts
 //---------------------------------------------------------
 
-void chainTrackParts(Track* t, bool incRefCount)
+void chainTrackParts(Track* t)
 {
   PartList* pl = t->parts();
-  for(iPart ip = pl->begin(); ip != pl->end(); ++ip)
-  {
-    Part* p = ip->second;
-    chainCheckErr(p);
-    
-    // Do we want to increase the reference count?
-    if(incRefCount)
-      p->events()->incARef(1);
-      
-    Part* p1 = 0;
-    
-    // Look for a part with the same event list, that we can chain to.
-    // It's faster if track type is known...
-    
-    if(!t || (t && t->isMidiTrack()))
-    {
-      MidiTrack* mt = 0;
-      MidiTrackList* mtl = MusEGlobal::song->midis();
-      for(ciMidiTrack imt = mtl->begin(); imt != mtl->end(); ++imt)
-      {
-        mt = *imt;
-        const PartList* pl = mt->cparts();
-        for(ciPart ip = pl->begin(); ip != pl->end(); ++ip)
-        {
-          if(ip->second != p && ip->second->cevents() == p->cevents())
-          {
-            p1 = ip->second;
-            break;
-          }
-        }
-        // If a suitable part was found on a different track, we're done. We will chain to it.
-        // Otherwise keep looking for parts on another track. If no others found, then we
-        //  chain to any suitable part which was found on the same given track t.
-        if(p1 && mt != t)
-          break;
-      }
-    }  
-    if((!p1 && !t) || (t && t->type() == Track::WAVE))
-    {
-      MusECore::WaveTrack* wt = 0;
-      MusECore::WaveTrackList* wtl = MusEGlobal::song->waves();
-      for(MusECore::ciWaveTrack iwt = wtl->begin(); iwt != wtl->end(); ++iwt)
-      {
-        wt = *iwt;
-        const PartList* pl = wt->cparts();
-        for(ciPart ip = pl->begin(); ip != pl->end(); ++ip)
-        {
-          if(ip->second != p && ip->second->cevents() == p->cevents())
-          {
-            p1 = ip->second;
-            break;
-          }
-        }
-        if(p1 && wt != t)
-          break;
-      }
-    }
-    
-    // No part found with same event list? Done.
-    if(!p1)
-      continue;
-      
-    // Make sure the part to be chained is unchained first.
-    p->prevClone()->setNextClone(p->nextClone());
-    p->nextClone()->setPrevClone(p->prevClone());
-    
-    // Link the part to be chained.
-    p->setPrevClone(p1);
-    p->setNextClone(p1->nextClone());
-    
-    // Re-link the existing part.
-    p1->nextClone()->setPrevClone(p);
-    p1->setNextClone(p);
-  }
+  for(riPart ip = pl->rbegin(); ip != pl->rend(); ++ip) // walk through in opposite direction than we unchained them.
+    ip->second->rechainClone();
 }
 
 //---------------------------------------------------------
@@ -372,8 +154,6 @@ void addPortCtrlEvents(Event& event, Part* part, bool doClones)
 {
   // Traverse and process the clone chain ring until we arrive at the same part again.
   // The loop is a safety net.
-  // Update: Due to the varying calls, and order of, incARefcount, (msg)ChangePart, replaceClone, and remove/addPortCtrlEvents,
-  //  we can not rely on the reference count as a safety net in these routines. We will just have to trust the clone chain.
   Part* p = part; 
   while(1)
   {
@@ -434,8 +214,6 @@ void addPortCtrlEvents(Part* part, bool doClones)
 {
   // Traverse and process the clone chain ring until we arrive at the same part again.
   // The loop is a safety net.
-  // Update: Due to the varying calls, and order of, incARefcount, (msg)ChangePart, replaceClone, and remove/addPortCtrlEvents,
-  //  we can not rely on the reference count as a safety net in these routines. We will just have to trust the clone chain.
   Part* p = part; 
   while(1)
   {
@@ -445,9 +223,8 @@ void addPortCtrlEvents(Part* part, bool doClones)
       MidiTrack* mt = (MidiTrack*)t;
       MidiPort* mp = &MusEGlobal::midiPorts[mt->outPort()];
       int ch = mt->outChannel();
-      const EventList* el = p->cevents();
       unsigned len = p->lenTick();
-      for(ciEvent ie = el->begin(); ie != el->end(); ++ie)
+      for(ciEvent ie = p->events().begin(); ie != p->events().end(); ++ie)
       {
         const Event& ev = ie->second;
         // Added by T356. Do not add events which are past the end of the part.
@@ -499,8 +276,6 @@ void removePortCtrlEvents(Event& event, Part* part, bool doClones)
 {
   // Traverse and process the clone chain ring until we arrive at the same part again.
   // The loop is a safety net.
-  // Update: Due to the varying calls, and order of, incARefcount, (msg)ChangePart, replaceClone, and remove/addPortCtrlEvents,
-  //  we can not rely on the reference count as a safety net in these routines. We will just have to trust the clone chain.
   Part* p = part; 
   while(1)
   {
@@ -555,8 +330,6 @@ void removePortCtrlEvents(Part* part, bool doClones)
 {
   // Traverse and process the clone chain ring until we arrive at the same part again.
   // The loop is a safety net.
-  // Update: Due to the varying calls, and order of, incARefcount, (msg)ChangePart, replaceClone, and remove/addPortCtrlEvents,
-  //  we can not rely on the reference count as a safety net in these routines. We will just have to trust the clone chain.
   Part* p = part; 
   while(1)
   {
@@ -566,16 +339,9 @@ void removePortCtrlEvents(Part* part, bool doClones)
       MidiTrack* mt = (MidiTrack*)t;
       MidiPort* mp = &MusEGlobal::midiPorts[mt->outPort()];
       int ch = mt->outChannel();
-      const EventList* el = p->cevents();
-      //unsigned len = p->lenTick();
-      for(ciEvent ie = el->begin(); ie != el->end(); ++ie)
+      for(ciEvent ie = p->events().begin(); ie != p->events().end(); ++ie)
       {
         const Event& ev = ie->second;
-        // Added by T356. Do not remove events which are past the end of the part. DELETETHIS 5
-        // No, actually, do remove ALL of them belonging to the part.
-        // Just in case there are stray values left after the part end.
-        //if(ev.tick() >= len)
-        //  break;
                           
         if(ev.type() == Controller)
         {
@@ -620,17 +386,18 @@ void removePortCtrlEvents(Part* part, bool doClones)
 
 iEvent Part::addEvent(Event& p)
       {
-      return _events->add(p);
+      assert(!hasClones());
+      return _events.add(p);
       }
 
 //---------------------------------------------------------
 //   index
 //---------------------------------------------------------
 
-int PartList::index(Part* part)
+int PartList::index(const Part* part) const
       {
       int index = 0;
-      for (iPart i = begin(); i != end(); ++i, ++index)
+      for (ciPart i = begin(); i != end(); ++i, ++index)
             if (i->second == part) {
                   return index;
                   }
@@ -652,65 +419,81 @@ Part* PartList::find(int idx)
       return 0;
       }
 
-//---------------------------------------------------------
-//   Part
-//---------------------------------------------------------
-
-Part::Part(const Part& p) : PosLen(p)
-{
-  _sn=p._sn;
-  _name=p._name;
-  _selected=p._selected;
-  _mute=p._mute;
-  _colorIndex=p._colorIndex;
-  _hiddenEvents=p._hiddenEvents;
-  _track=p._track;
-  _events=p._events;
-  _prevClone=p._prevClone;
-  _nextClone=p._nextClone;
-  
-  _events->incRef(1);
-}
-
 Part::Part(Track* t)
       {
       _hiddenEvents = NoEventsHidden;
       _prevClone = this;
       _nextClone = this;
-      setSn(newSn());
+      _backupClone = NULL;
+      _sn = newSn();
+      _clonemaster_sn = _sn;
       _track      = t;
       _selected   = false;
       _mute       = false;
       _colorIndex = 0;
-      _events     = new EventList;
-      _events->incRef(1);
-      _events->incARef(1);
       }
 
-Part::Part(Track* t, EventList* ev)
-      {
-      _hiddenEvents = NoEventsHidden;
-      _prevClone = this;
-      _nextClone = this;
-      setSn(newSn());
-      _track      = t;
-      _selected   = false;
-      _mute       = false;
-      _colorIndex = 0;
-      _events     = ev;
-      _events->incRef(1);
-      _events->incARef(1);
-      }
+WavePart* WavePart::duplicateEmpty() const
+{
+	WavePart* part = new WavePart((WaveTrack*)this->_track);
+	part->setName(name());
+	part->setColorIndex(colorIndex());
+
+	*(PosLen*)part = *(PosLen*)this;
+	part->setMute(mute());
+	
+	return part;
+}
 
-//---------------------------------------------------------
-//   MidiPart
-//   copy constructor
-//---------------------------------------------------------
+WavePart* WavePart::duplicate() const
+{
+	return (WavePart*)Part::duplicate();
+}
 
-MidiPart::MidiPart(const MidiPart& p) : Part(p)
+WavePart* WavePart::createNewClone() const
 {
-  _prevClone = this;
-  _nextClone = this;
+	return (WavePart*)Part::createNewClone();
+}
+
+MidiPart* MidiPart::duplicateEmpty() const
+{
+	MidiPart* part = new MidiPart((MidiTrack*)this->_track);
+	part->setName(name());
+	part->setColorIndex(colorIndex());
+
+	*(PosLen*)part = *(PosLen*)this;
+	part->setMute(mute());
+	
+	return part;
+}
+
+MidiPart* MidiPart::duplicate() const
+{
+	return (MidiPart*)Part::duplicate();
+}
+
+MidiPart* MidiPart::createNewClone() const
+{
+	return (MidiPart*)Part::createNewClone();
+}
+
+
+Part* Part::createNewClone() const
+{
+	Part* clone = duplicate();
+	clone->_backupClone=const_cast<Part*>(this);
+	return clone;
+}
+
+Part* Part::duplicate() const
+{
+	Part* dup = duplicateEmpty();
+
+	// copy the eventlist; duplicate each Event(Ptr!).
+	for (MusECore::ciEvent i = _events.begin(); i != _events.end(); ++i)
+		dup->_events.add(i->second.clone());
+
+	return dup;
 }
 
 
@@ -724,42 +507,21 @@ WavePart::WavePart(WaveTrack* t)
       setType(FRAMES);
       }
 
-WavePart::WavePart(WaveTrack* t, EventList* ev)
-   : Part(t, ev)
-      {
-      setType(FRAMES);
-      }
-
-//---------------------------------------------------------
-//   WavePart
-//   copy constructor
-//---------------------------------------------------------
-
-WavePart::WavePart(const WavePart& p) : Part(p)
-{
-  _prevClone = this;
-  _nextClone = this;
-}
-
 
 //---------------------------------------------------------
 //   Part
 //---------------------------------------------------------
 
 Part::~Part()
-      {
+{
       if (_prevClone!=this || _nextClone!=this)
       {
         if (MusEGlobal::debugMsg) {
             fprintf(stderr, "Part isn't unchained in ~Part()! Unchaining now...\n");
         }
-        unchainClone(this);
-      }
-        
-      _events->incRef(-1);
-      if (_events->refCount() <= 0)
-            delete _events;
-      }
+        unchainClone();
+      }  
+}
 
 
 //---------------------------------------------------------
@@ -852,55 +614,24 @@ void Song::cmdResizePart(Track* track, Part* oPart, unsigned int len, bool doClo
       switch(track->type()) {
             case Track::WAVE:
                   {
-                  MusECore::WavePart* nPart = new MusECore::WavePart(*(MusECore::WavePart*)oPart);
-                  EventList* el = nPart->events();
-                  unsigned new_partlength = MusEGlobal::tempomap.deltaTick2frame(oPart->tick(), oPart->tick() + len);
-
-                  // If new nr of frames is less than previous what can happen is:
-                  // -   0 or more events are beginning after the new final position. Those are removed from the part
-                  // -   The last event begins before new final position and ends after it. If so, it will be resized to end at new part length
-                  if (new_partlength < oPart->lenFrame()) {
-                        Undo operations;
-
-                        for (iEvent i = el->begin(); i != el->end(); i++) {
-                              Event e = i->second;
-                              unsigned event_startframe = e.frame();
-                              unsigned event_endframe = event_startframe + e.lenFrame();
-                              if (event_endframe < new_partlength)
-                                    continue;
-                              }
-                        nPart->setLenFrame(new_partlength);
-                        // Do not do port controller values and clone parts. 
-                        operations.push_back(UndoOp(UndoOp::ModifyPart, oPart, nPart, false, false));
-
-                        MusEGlobal::song->applyOperationGroup(operations);
-                        }
-                  // If the part is expanded there can be no additional events beginning after the previous final position
-                  // since those are removed if the part has been shrunk at some time (see above)
-                  // The only thing we need to check is the final event: If it has data after the previous final position,
-                  // we'll expand that event
-                  else {
-                        Undo operations;
-                        if(!el->empty())
-                        {
-                          iEvent i = el->end();
-                          i--;
-                          Event last = i->second;
-                          MusECore::SndFileR file = last.sndFile();
-                          if (file.isNull())
-                                return;
-                          Event newEvent = last.clone();
-                          // Do not do port controller values and clone parts. 
-                          operations.push_back(UndoOp(UndoOp::ModifyEvent, newEvent, last, nPart, false, false));
-                        }  
-                        
-                        nPart->setLenFrame(new_partlength);
-                        // Do not do port controller values and clone parts. 
-                        operations.push_back(UndoOp(UndoOp::ModifyPart, oPart, nPart, false, false));
-                        MusEGlobal::song->applyOperationGroup(operations);
-                        }
-                  }
+                  Undo operations;
+									
+									unsigned orig_len=oPart->lenFrame();
+									WavePart* part_it=(WavePart*)oPart;
+									do
+									{
+										if (part_it->lenFrame()==orig_len)
+										{
+											// Do port controller values but not clone parts. 
+											operations.push_back(UndoOp(UndoOp::ModifyPartLengthFrames, part_it, part_it->lenFrame(), len, true, false));
+										}
+										
+										part_it=(WavePart*)part_it->nextClone();
+									} while (doClones && (part_it != (WavePart*)oPart));
+                  
+                  MusEGlobal::song->applyOperationGroup(operations);
                   break;
+                  }
             case Track::MIDI:
             case Track::DRUM:
             case Track::NEW_DRUM:
@@ -913,10 +644,8 @@ void Song::cmdResizePart(Track* track, Part* oPart, unsigned int len, bool doClo
 									{
 										if (part_it->lenTick()==orig_len)
 										{
-											MidiPart* newPart = new MidiPart(*part_it);
-											newPart->setLenTick(len);
 											// Do port controller values but not clone parts. 
-											operations.push_back(UndoOp(UndoOp::ModifyPart, part_it, newPart, true, false));
+											operations.push_back(UndoOp(UndoOp::ModifyPartLength, part_it, part_it->lenTick(), len, true, false));
 										}
 										
 										part_it=(MidiPart*)part_it->nextClone();
@@ -936,23 +665,23 @@ void Song::cmdResizePart(Track* track, Part* oPart, unsigned int len, bool doClo
 //    create two new parts p1 and p2
 //---------------------------------------------------------
 
-void Track::splitPart(Part* part, int tickpos, Part*& p1, Part*& p2)
+void Part::splitPart(int tickpos, Part*& p1, Part*& p2) const
       {
       int l1 = 0;       // len of first new part (ticks or samples)
       int l2 = 0;       // len of second new part
 
       int samplepos = MusEGlobal::tempomap.tick2frame(tickpos);
 
-      switch (type()) {
-            case WAVE:
-                  l1 = samplepos - part->frame();
-                  l2 = part->lenFrame() - l1;
+      switch (track()->type()) {
+          case Track::WAVE:
+                  l1 = samplepos - frame();
+                  l2 = lenFrame() - l1;
                   break;
-            case MIDI:
-            case DRUM:
-            case NEW_DRUM:
-                  l1 = tickpos - part->tick();
-                  l2 = part->lenTick() - l1;
+          case Track::MIDI:
+          case Track::DRUM:
+          case Track::NEW_DRUM:
+                  l1 = tickpos - tick();
+                  l2 = lenTick() - l1;
                   break;
             default:
                   return;
@@ -961,20 +690,18 @@ void Track::splitPart(Part* part, int tickpos, Part*& p1, Part*& p2)
       if (l1 <= 0 || l2 <= 0)
             return;
 
-      p1 = newPart(part);     // new left part
-      p2 = newPart(part);     // new right part
+      p1 = this->duplicateEmpty();   // new left part
+      p2 = this->duplicateEmpty();   // new right part
 
-      // Added by Tim. p3.3.6
-      
-      switch (type()) {
-            case WAVE:
+      switch (track()->type()) {
+          case Track::WAVE:
                   p1->setLenFrame(l1);
                   p2->setFrame(samplepos);
                   p2->setLenFrame(l2);
                   break;
-            case MIDI:
-            case DRUM:
-            case NEW_DRUM:
+          case Track::MIDI:
+          case Track::DRUM:
+          case Track::NEW_DRUM:
                   p1->setLenTick(l1);
                   p2->setTick(tickpos);
                   p2->setLenTick(l2);
@@ -983,158 +710,41 @@ void Track::splitPart(Part* part, int tickpos, Part*& p1, Part*& p2)
                   break;
             }
 
-      p2->setSn(p2->newSn());
-
-      EventList* se  = part->events();
-      EventList* de1 = p1->events();
-      EventList* de2 = p2->events();
-
-      if (type() == WAVE) {
-            int ps   = part->frame();
+      if (track()->type() == Track::WAVE) {
+            int ps   = this->frame();
             int d1p1 = p1->frame();
             int d2p1 = p1->endFrame();
             int d1p2 = p2->frame();
             int d2p2 = p2->endFrame();
-            for (iEvent ie = se->begin(); ie != se->end(); ++ie) {
-                  Event event = ie->second;
+            for (ciEvent ie = _events.begin(); ie != _events.end(); ++ie) {
+                  const Event& event = ie->second;
                   int s1 = event.frame() + ps;
                   int s2 = event.endFrame() + ps;
                   
                   if ((s2 > d1p1) && (s1 < d2p1)) {
                         Event si = event.mid(d1p1 - ps, d2p1 - ps);
-                        de1->add(si);
+                        p1->_events.add(si);
                         }
                   if ((s2 > d1p2) && (s1 < d2p2)) {
                         Event si = event.mid(d1p2 - ps, d2p2 - ps);
-                        de2->add(si);
+                        p2->_events.add(si);
                         }
                   }
             }
       else {
-            for (iEvent ie = se->begin(); ie != se->end(); ++ie) {
+            for (ciEvent ie = _events.begin(); ie != _events.end(); ++ie) {
                   Event event = ie->second.clone();
                   int t = event.tick();
                   if (t >= l1) {
                         event.move(-l1);
-                        de2->add(event);
+                        p2->_events.add(event);
                         }
                   else
-                        de1->add(event);
+                        p1->_events.add(event);
                   }
             }
       }
 
-//---------------------------------------------------------
-//   cmdSplitPart
-//---------------------------------------------------------
-
-void Song::cmdSplitPart(Track* track, Part* part, int tick)
-      {
-      int l1 = tick - part->tick();
-      int l2 = part->lenTick() - l1;
-      if (l1 <= 0 || l2 <= 0)
-            return;
-      Part* p1;
-      Part* p2;
-      track->splitPart(part, tick, p1, p2);
-      
-      //MusEGlobal::song->informAboutNewParts(part, p1); // is unneccessary because of ChangePart below
-      MusEGlobal::song->informAboutNewParts(part, p2);
-
-      startUndo();
-      // Indicate no undo, and do port controller values but not clone parts. 
-      MusEGlobal::audio->msgChangePart(part, p1, false, true, false);
-      MusEGlobal::audio->msgAddPart(p2, false);
-      endUndo(SC_TRACK_MODIFIED | SC_PART_MODIFIED | SC_PART_INSERTED);
-      }
-
-//---------------------------------------------------------
-//   changePart
-//---------------------------------------------------------
-
-void Song::changePart(Part* oPart, Part* nPart)
-      {
-      nPart->setSn(oPart->sn());
-
-      Track* oTrack = oPart->track();
-      Track* nTrack = nPart->track();
-
-      oTrack->parts()->remove(oPart);
-      nTrack->parts()->add(nPart);
-      
-      
-      // Added by T356. 
-      // adjust song len:
-      unsigned epos = nPart->tick() + nPart->lenTick();
-      if (epos > len())
-            _len = epos;
-      
-      }
-
-//---------------------------------------------------------
-//   cmdGluePart
-//---------------------------------------------------------
-
-void Song::cmdGluePart(Track* track, Part* oPart)
-      {
-      // p3.3.54
-      if(track->type() != Track::WAVE && !track->isMidiTrack())
-        return;
-      
-      PartList* pl   = track->parts();
-      Part* nextPart = 0;
-
-      for (iPart ip = pl->begin(); ip != pl->end(); ++ip) {
-            if (ip->second == oPart) {
-                  ++ip;
-                  if (ip == pl->end())
-                        return;
-                  nextPart = ip->second;
-                  break;
-                  }
-            }
-
-      Part* nPart = track->newPart(oPart);
-      nPart->setLenTick(nextPart->tick() + nextPart->lenTick() - oPart->tick());
-
-      // populate nPart with Events from oPart and nextPart
-
-      EventList* sl1 = oPart->events();
-      EventList* dl  = nPart->events();
-
-      for (iEvent ie = sl1->begin(); ie != sl1->end(); ++ie)
-            dl->add(ie->second);
-
-      EventList* sl2 = nextPart->events();
-      
-      if(track->type() == Track::WAVE)
-      {
-        int frameOffset = nextPart->frame() - oPart->frame();
-        for (iEvent ie = sl2->begin(); ie != sl2->end(); ++ie) 
-        {
-              Event event = ie->second.clone();
-              event.setFrame(event.frame() + frameOffset);
-              dl->add(event);
-        }
-      }
-      else
-      if(track->isMidiTrack())
-      {
-        int tickOffset  = nextPart->tick() - oPart->tick();
-        for (iEvent ie = sl2->begin(); ie != sl2->end(); ++ie) 
-        {
-              Event event = ie->second.clone();
-              event.setTick(event.tick() + tickOffset);
-              dl->add(event);
-        }
-      }
-            
-      startUndo();
-      MusEGlobal::audio->msgRemovePart(nextPart, false);
-      // Indicate no undo, and do port controller values but not clone parts. 
-      MusEGlobal::audio->msgChangePart(oPart, nPart, false, true, false);
-      endUndo(SC_PART_MODIFIED | SC_PART_REMOVED);
-      }
 
 //---------------------------------------------------------
 //   dump
@@ -1169,21 +779,6 @@ void MidiPart::dump(int n) const
       }
 
 //---------------------------------------------------------
-//   clone
-//---------------------------------------------------------
-
-MidiPart* MidiPart::clone() const
-      {
-      return new MidiPart(*this);
-      }
-
-
-WavePart* WavePart::clone() const
-      {
-      return new WavePart(*this);
-      }
-
-//---------------------------------------------------------
 //   hasHiddenEvents
 //   Returns combination of HiddenEventsType enum.
 //---------------------------------------------------------
@@ -1193,7 +788,7 @@ int MidiPart::hasHiddenEvents()
   unsigned len = lenTick();
 
   // TODO: For now, we don't support events before the left border, only events past the right border.
-  for(iEvent ev=events()->begin(); ev!=events()->end(); ev++)
+  for(ciEvent ev=_events.begin(); ev!=_events.end(); ev++)
   {
     if(ev->second.endTick() > len)
     {
@@ -1215,7 +810,7 @@ int WavePart::hasHiddenEvents()
   unsigned len = lenFrame();
   
   // TODO: For now, we don't support events before the left border, only events past the right border.
-  for(iEvent ev=events()->begin(); ev!=events()->end(); ev++)
+  for(ciEvent ev=_events.begin(); ev!=_events.end(); ev++)
   {
     if(ev->second.endFrame() > len)
     {
diff --git a/muse2/muse/part.h b/muse2/muse/part.h
index 357ec1db..02056a2d 100644
--- a/muse2/muse/part.h
+++ b/muse2/muse/part.h
@@ -60,16 +60,13 @@ typedef CloneList::iterator iClone;
 class Part : public PosLen {
    public:
       enum HiddenEventsType { NoEventsHidden = 0, LeftEventsHidden, RightEventsHidden };
-   
-   // @@@@@@@@@@@ IMPORTANT @@@@@@@@@@@@
-   // @@ when adding member variables @@
-   // @@ here, don't forget to update @@
-   // @@ the copy-constructor!        @@
-   // @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+      
+      static Part* readFromXml(Xml&, Track*, bool doClone = false, bool toTrack = true);
    
    private:
       static int snGen;
       int _sn;
+      int _clonemaster_sn; // the serial number of some clone in the chain. every member of the chain has the same value here.
 
       QString _name;
       bool _selected;
@@ -78,22 +75,24 @@ class Part : public PosLen {
                    
    protected:
       Track* _track;
-      EventList* _events;
+      EventList _events;
       Part* _prevClone;
       Part* _nextClone;
+      Part* _backupClone; // when a part gets removed, it's still there; and for undo-ing the remove, it must know about where it was clone-chained to.
       int _hiddenEvents;   // Combination of HiddenEventsType.
-                   
+
    public:
       Part(Track*);
-      Part(Track*, EventList*);
-      Part(const Part& p);
       virtual ~Part();
-      int sn()                         { return _sn; }
-      void setSn(int n)                { _sn = n; }
+      virtual Part* duplicate() const;
+      virtual Part* duplicateEmpty() const = 0;
+      virtual Part* createNewClone() const; // this does NOT chain clones yet. Chain is updated only when the part is really added!
+      virtual void splitPart(int tickpos, Part*& p1, Part*& p2) const;
+      
+      int clonemaster_sn() const       { return _clonemaster_sn; }
+      int sn() const                   { return _sn; }
       int newSn()                      { return snGen++; }
 
-      virtual Part* clone() const = 0;
-
       const QString& name() const      { return _name; }
       void setName(const QString& s)   { _name = s; }
       bool selected() const            { return _selected; }
@@ -102,23 +101,26 @@ class Part : public PosLen {
       void setMute(bool b)             { _mute = b; }
       Track* track() const             { return _track; }
       void setTrack(Track*t)           { _track = t; }
-      EventList* events() const        { return _events; }
-      const EventList* cevents() const { return _events; }
+      const EventList& events() const  { return _events; }
+      EventList& nonconst_events()     { return _events; }
       int colorIndex() const           { return _colorIndex; }
       void setColorIndex(int idx)      { _colorIndex = idx; }
       
-      Part* prevClone()                { return _prevClone; }
-      Part* nextClone()                { return _nextClone; }
-      void setPrevClone(Part* p)       { _prevClone = p; }
-      void setNextClone(Part* p)       { _nextClone = p; }
+      bool isCloneOf(const Part*) const;
+      bool hasClones() const           { return _prevClone!=this || _nextClone!=this; }
+      int nClones() const;
+      Part* prevClone() const          { return _prevClone; } // FINDMICHJETZT make it const Part*!
+      Part* nextClone() const          { return _nextClone; }
+      Part* backupClone() const        { return _backupClone; }
+      
+      void unchainClone();
+      void chainClone(Part* p); // *this is made a sibling of p! p is not touched (except for its clone-chain), whereas this->events will get altered
+      void rechainClone(); // re-chains the part to the same clone chain it was unchained before
       
       // Returns combination of HiddenEventsType enum.
-      virtual int hasHiddenEvents() = 0;
-      // If repeated calls to hasHiddenEvents() are desired, then to avoid re-iteration of the event list, 
-      //  call this after hasHiddenEvents().
-      int cachedHasHiddenEvents() const { return _hiddenEvents; }
+      virtual int hasHiddenEvents() const { return _hiddenEvents; }
       
-      iEvent addEvent(Event& p);
+      iEvent addEvent(Event& p); // DEPRECATED. requires the part to be NOT a clone. FIXME remove!
 
       virtual void write(int, Xml&, bool isCopy = false, bool forceWavePaths = false) const;
       
@@ -134,10 +136,12 @@ class MidiPart : public Part {
 
    public:
       MidiPart(MidiTrack* t) : Part((Track*)t) {}
-      MidiPart(MidiTrack* t, EventList* ev) : Part((Track*)t, ev) {}
-      MidiPart(const MidiPart& p);
       virtual ~MidiPart() {}
-      virtual MidiPart* clone() const;
+      virtual MidiPart* duplicate() const;
+      virtual MidiPart* duplicateEmpty() const;
+      virtual MidiPart* createNewClone() const;
+
+      
       MidiTrack* track() const   { return (MidiTrack*)Part::track(); }
       // Returns combination of HiddenEventsType enum.
       int hasHiddenEvents();
@@ -154,13 +158,14 @@ class WavePart : public Part {
 
       // p3.3.31
       AudioConvertMap _converters;
-      
+
    public:
       WavePart(WaveTrack* t);
-      WavePart(WaveTrack* t, EventList* ev);
-      WavePart(const WavePart& p);
       virtual ~WavePart() {}
-      virtual WavePart* clone() const;
+      virtual WavePart* duplicate() const;
+      virtual WavePart* duplicateEmpty() const;
+      virtual WavePart* createNewClone() const;
+
       WaveTrack* track() const   { return (WaveTrack*)Part::track(); }
       // Returns combination of HiddenEventsType enum.
       int hasHiddenEvents();
@@ -182,7 +187,7 @@ class PartList : public std::multimap<int, Part*, std::less<unsigned> > {
       iPart findPart(unsigned tick);
       iPart add(Part*);
       void remove(Part* part);
-      int index(Part*);
+      int index(const Part*) const;
       Part* find(int idx);
       void clearDelete() {
             for (iPart i = begin(); i != end(); ++i)
@@ -191,18 +196,13 @@ class PartList : public std::multimap<int, Part*, std::less<unsigned> > {
             }
       };
 
-extern void chainClone(Part* p);
-extern void chainClone(Part* p1, Part* p2);
-extern void unchainClone(Part* p);
-extern void replaceClone(Part* p1, Part* p2);
 extern void chainCheckErr(Part* p);
-extern void unchainTrackParts(Track* t, bool decRefCount);
-extern void chainTrackParts(Track* t, bool incRefCount);
+extern void unchainTrackParts(Track* t);
+extern void chainTrackParts(Track* t);
 extern void addPortCtrlEvents(Part* part, bool doClones);
 extern void addPortCtrlEvents(Event& event, Part* part, bool doClones);
 extern void removePortCtrlEvents(Part* part, bool doClones);
 extern void removePortCtrlEvents(Event& event, Part* part, bool doClones);
-extern Part* readXmlPart(Xml&, Track*, bool doClone = false, bool toTrack = true);
 
 } // namespace MusECore
 
diff --git a/muse2/muse/remote/pyapi.cpp b/muse2/muse/remote/pyapi.cpp
index 7e03fa0e..8f5abe06 100644
--- a/muse2/muse/remote/pyapi.cpp
+++ b/muse2/muse/remote/pyapi.cpp
@@ -199,9 +199,9 @@ PyObject* getParts(PyObject*, PyObject* args)
                   Py_DECREF(pstrtick2);
 
                   // Pack midi events into list before wrapping it all up
-                  EventList* events = mpart->events();
+                  const EventList& events = mpart->events();
                   PyObject* pyevents = Py_BuildValue("[]");
-                  for (ciEvent e = events->begin(); e != events->end(); e++) {
+                  for (ciEvent e = events.begin(); e != events.end(); e++) {
                         PyObject* pyevent = PyDict_New(); // The event structure - a dictionary with keys 'type','tick','data'
 
                         const Event& event = e->second;
@@ -331,7 +331,7 @@ bool addPyPartEventsToMusePart(MidiPart* npart, PyObject* part)
                   event.setC(data[2]);
                   event.setTick(etick);
                   event.setLenTick(elen);
-                  npart->events()->add(event);
+                  npart->nonconst_events().add(event);
                   }
             else
                   printf("Unhandled event type from python: %s\n", type.c_str());
@@ -404,12 +404,12 @@ PyObject* modifyPart(PyObject*, PyObject* part)
       npart->setLenTick(opart->lenTick());
       npart->setSn(opart->sn());
        
-      for (iEvent e = opart->events()->begin(); e != opart->events()->end(); e++) {
+      for (ciEvent e = opart->events().begin(); e != opart->events().end(); e++) {
             Event& event = e->second;
             if (event.type() == Note || event.type() == Controller) 
                   continue;
 
-            npart->events()->add(event);
+            npart->nonconst_events()->add(event);
             }
 
       addPyPartEventsToMusePart(npart, part);
@@ -1131,9 +1131,7 @@ bool Song::event(QEvent* _e)
                   break;
                   }
             case QPybridgeEvent::SONG_ADD_TRACK: {
-                  MusECore::Undo operations;
-                  MusEGlobal::song->addTrack(operations, (Track::TrackType)e->getP1());  // Add at end of list.
-                  MusEGlobal::song->applyOperationGroup(operations);
+                  MusEGlobal::song->addTrack((Track::TrackType)e->getP1());  // Add at end of list.
                   break;
                   }
             case QPybridgeEvent::SONG_CHANGE_TRACKNAME: {
diff --git a/muse2/muse/seqmsg.cpp b/muse2/muse/seqmsg.cpp
index fcffc332..669aff9d 100644
--- a/muse2/muse/seqmsg.cpp
+++ b/muse2/muse/seqmsg.cpp
@@ -319,38 +319,6 @@ void Audio::msgSetRecord(AudioTrack* node, bool val)
       sendMsg(&msg);
       }
 
-/* DELETETHIS 34
-//---------------------------------------------------------
-//   msgSetVolume
-//---------------------------------------------------------
-
-void Audio::msgSetVolume(AudioTrack* src, double val)
-      {
-      AudioMsg msg;
-      msg.id    = AUDIO_VOL;
-      msg.snode    = src;
-      msg.dval  = val;
-      sendMsg(&msg);
-      //muse->arranger->controllerChanged(src);
-      MusEGlobal::song->controllerChange(src);
-      }
-
-//---------------------------------------------------------
-//   msgSetPan
-//---------------------------------------------------------
-
-void Audio::msgSetPan(AudioTrack* node, double val)
-      {
-      AudioMsg msg;
-      msg.id    = AUDIO_PAN;
-      msg.snode = node;
-      msg.dval  = val;
-      sendMsg(&msg);
-      //muse->arranger->controllerChanged(node);
-      MusEGlobal::song->controllerChange(node);
-      }
-*/
-
 //---------------------------------------------------------
 //   msgSetPrefader
 //---------------------------------------------------------
@@ -492,26 +460,6 @@ void Audio::msgSetChannels(AudioTrack* node, int n)
       sendMsg(&msg);
       }
 
-/* DELETETHIS 20
-//---------------------------------------------------------
-//   msgSetPluginCtrlVal
-//---------------------------------------------------------
-
-void Audio::msgSetPluginCtrlVal(AudioTrack* track, int param, double val)
-{
-      AudioMsg msg;
-      
-      msg.id     = AUDIO_SET_PLUGIN_CTRL_VAL;
-      msg.ival   = param;
-      msg.dval   = val;
-      //msg.plugin = plugin;
-      msg.snode  = track;
-      sendMsg(&msg);
-      //muse->arranger->controllerChanged(track);
-      MusEGlobal::song->controllerChange(track);
-}
-*/
-
 //---------------------------------------------------------
 //   msgSwapControllerIDX
 //---------------------------------------------------------
@@ -646,18 +594,6 @@ void Audio::msgSetSolo(Track* track, bool val)
       sendMsg(&msg);
 }
 
-//---------------------------------------------------------
-//   msgSetSegSize
-//---------------------------------------------------------
-
-void Audio::msgSetSegSize(int bs, int sr)
-      {
-      AudioMsg msg;
-      msg.id = AUDIO_SET_SEG_SIZE;
-      msg.ival = bs;
-      msg.iival = sr;
-      sendMsg(&msg);
-      }
 
 //---------------------------------------------------------
 //   msgSeek
@@ -670,26 +606,37 @@ void Audio::msgSeek(const Pos& pos)
       }
 
 //---------------------------------------------------------
-//   msgUndo
+//   msgExecuteOperationGroup
 //---------------------------------------------------------
 
-void Audio::msgUndo()
-      {
-      AudioMsg msg;
-      msg.id = SEQM_UNDO;
-      sendMsg(&msg);
-      }
+void Audio::msgExecuteOperationGroup(Undo& operations)
+{
+	MusEGlobal::song->executeOperationGroup1(operations);
+	
+	AudioMsg msg;
+	msg.id = SEQM_EXECUTE_OPERATION_GROUP;
+	msg.operations=&operations;
+	sendMsg(&msg);
+
+	MusEGlobal::song->executeOperationGroup3(operations);
+}
 
 //---------------------------------------------------------
-//   msgRedo
+//   msgRevertOperationGroup
 //---------------------------------------------------------
 
-void Audio::msgRedo()
-      {
-      AudioMsg msg;
-      msg.id = SEQM_REDO;
-      sendMsg(&msg);
-      }
+void Audio::msgRevertOperationGroup(Undo& operations)
+{
+	MusEGlobal::song->revertOperationGroup1(operations);
+	
+	
+	AudioMsg msg;
+	msg.id = SEQM_REVERT_OPERATION_GROUP;
+	msg.operations=&operations;
+	sendMsg(&msg);
+
+	MusEGlobal::song->revertOperationGroup3(operations);
+}
 
 //---------------------------------------------------------
 //   msgPlay
@@ -714,56 +661,7 @@ void Audio::msgPlay(bool val)
             }
       }
 
-/* DELETETHIS 31
-//---------------------------------------------------------
-//   msgShowInstrumentGui
-//---------------------------------------------------------
-
-void Audio::msgShowInstrumentGui(MidiInstrument* instr, bool val)
-      {
-      instr->showGui(val);
-      // No need for this - it called msgUpdatePollFd which has nothing
-      //  to do with showing a gui.
-      //AudioMsg msg;
-      //msg.id = MIDI_SHOW_INSTR_GUI;
-      //msg.p1 = instr;
-      //msg.a  = val;
-      //sendMessage(&msg, false);
-      }
-
-//---------------------------------------------------------
-//   msgShowInstrumentNativeGui
-//---------------------------------------------------------
-
-void Audio::msgShowInstrumentNativeGui(MidiInstrument* instr, bool val)
-      {
-      instr->showNativeGui(val);
-      //AudioMsg msg;
-      //msg.id = MIDI_SHOW_INSTR_NATIVE_GUI;
-      //msg.p1 = instr;
-      //msg.a  = val;
-      //sendMessage(&msg, false);
-      }
-*/
-
-//---------------------------------------------------------
-//   msgAddTrack
-//---------------------------------------------------------
 
-void Song::msgInsertTrack(Track* track, int idx, bool doUndoFlag)
-      {
-      AudioMsg msg;
-      msg.id = SEQM_ADD_TRACK;
-      msg.track = track;
-      msg.ival  = idx;
-      if (doUndoFlag) {
-            MusEGlobal::song->startUndo();
-            addUndo(UndoOp(UndoOp::AddTrack, idx, track));
-            }
-      MusEGlobal::audio->sendMsg(&msg);
-      if (doUndoFlag)
-            endUndo(SC_TRACK_INSERTED);
-      }
 
 //---------------------------------------------------------
 //   msgRemoveTrack
@@ -771,10 +669,7 @@ void Song::msgInsertTrack(Track* track, int idx, bool doUndoFlag)
 
 void Audio::msgRemoveTrack(Track* track, bool doUndoFlag)
       {
-      AudioMsg msg;
-      msg.id = SEQM_REMOVE_TRACK;
-      msg.track = track;
-      sendMessage(&msg, doUndoFlag);
+      MusEGlobal::song->applyOperation(UndoOp(UndoOp::DeleteTrack, MusEGlobal::song->tracks()->index(track), track), doUndoFlag);
       }
 
 //---------------------------------------------------------
@@ -794,9 +689,7 @@ void Audio::msgRemoveTracks()
           Track* tr = *t;
           if (tr->selected()) 
           {
-            MusEGlobal::song->removeTrack1(tr);
-            msgRemoveTrack(tr, false);
-            MusEGlobal::song->removeTrack3(tr);
+            MusEGlobal::song->applyOperation(UndoOp(UndoOp::DeleteTrack, MusEGlobal::song->tracks()->index(tr), tr), false);
             loop = true;
             break;
           }
@@ -834,23 +727,6 @@ void Audio::msgRemoveTracks()
             
 }
 
-/*    DELETETHIS 18
-//---------------------------------------------------------
-//   msgChangeTrack
-//    oldTrack - copy of the original track befor modification
-//    newTrack - modified original track
-//---------------------------------------------------------
-
-void Audio::msgChangeTrack(Track* oldTrack, Track* newTrack, bool doUndoFlag)   
-      {
-      AudioMsg msg;
-      msg.id = SEQM_CHANGE_TRACK;
-      msg.p1 = oldTrack;
-      msg.p2 = newTrack;
-      sendMessage(&msg, doUndoFlag);
-      }
-*/
-     
 //---------------------------------------------------------
 //   msgMoveTrack
 //    move track idx1 to slot idx2
@@ -863,11 +739,7 @@ void Audio::msgMoveTrack(int idx1, int idx2, bool doUndoFlag)
       int n = MusEGlobal::song->tracks()->size();
       if (idx1 >= n || idx2 >= n)   // sanity check
             return;
-      AudioMsg msg;
-      msg.id = SEQM_MOVE_TRACK;
-      msg.a = idx1;
-      msg.b = idx2;
-      sendMessage(&msg, doUndoFlag);
+      MusEGlobal::song->applyOperation(UndoOp(UndoOp::SwapTrack, idx1, idx2), doUndoFlag);
       }
 
 //---------------------------------------------------------
@@ -876,10 +748,7 @@ void Audio::msgMoveTrack(int idx1, int idx2, bool doUndoFlag)
 
 void Audio::msgAddPart(Part* part, bool doUndoFlag)
       {
-      AudioMsg msg;
-      msg.id = SEQM_ADD_PART;
-      msg.p1 = part;
-      sendMessage(&msg, doUndoFlag);
+      MusEGlobal::song->applyOperation(UndoOp(UndoOp::AddPart, part), doUndoFlag);
       }
 
 //---------------------------------------------------------
@@ -888,54 +757,9 @@ void Audio::msgAddPart(Part* part, bool doUndoFlag)
 
 void Audio::msgRemovePart(Part* part, bool doUndoFlag)
       {
-      AudioMsg msg;
-      msg.id = SEQM_REMOVE_PART;
-      msg.p1 = part;
-      sendMessage(&msg, doUndoFlag);
-      }
-
-//---------------------------------------------------------
-//   msgRemoveParts
-//    remove selected parts; return true if any part was
-//    removed
-//---------------------------------------------------------
-
-bool Song::msgRemoveParts()
-      {
-      Undo operations;
-      bool partSelected = false;
-
-            TrackList* tl = MusEGlobal::song->tracks();
-
-            for (iTrack it = tl->begin(); it != tl->end(); ++it) {
-                  PartList* pl = (*it)->parts();
-                  for (iPart ip = pl->begin(); ip != pl->end(); ++ip) {
-                        if (ip->second->selected()) {
-                              operations.push_back(UndoOp(UndoOp::DeletePart,ip->second));
-                              partSelected = true;
-                              }
-                        }
-                  }
-      
-      MusEGlobal::song->applyOperationGroup(operations);
-      
-      return partSelected;
+      MusEGlobal::song->applyOperation(UndoOp(UndoOp::DeletePart, part), doUndoFlag);
       }
 
-//---------------------------------------------------------
-//   msgChangePart
-//---------------------------------------------------------
-
-void Audio::msgChangePart(Part* oldPart, Part* newPart, bool doUndoFlag, bool doCtrls, bool doClones)
-      {
-      AudioMsg msg;
-      msg.id = SEQM_CHANGE_PART;
-      msg.p1 = oldPart;
-      msg.p2 = newPart;
-      msg.a = doCtrls;
-      msg.b = doClones;
-      sendMessage(&msg, doUndoFlag);
-      }
 
 //---------------------------------------------------------
 //   msgAddEvent
@@ -943,13 +767,7 @@ void Audio::msgChangePart(Part* oldPart, Part* newPart, bool doUndoFlag, bool do
 
 void Audio::msgAddEvent(Event& event, Part* part, bool doUndoFlag, bool doCtrls, bool doClones)
       {
-      AudioMsg msg;
-      msg.id = SEQM_ADD_EVENT;
-      msg.ev1 = event;
-      msg.p2 = part;
-      msg.a = doCtrls;
-      msg.b = doClones;
-      sendMessage(&msg, doUndoFlag);
+      MusEGlobal::song->applyOperation(UndoOp(UndoOp::AddEvent, event,part, doCtrls, doClones), doUndoFlag);
       }
 
 //---------------------------------------------------------
@@ -958,13 +776,7 @@ void Audio::msgAddEvent(Event& event, Part* part, bool doUndoFlag, bool doCtrls,
 
 void Audio::msgDeleteEvent(Event& event, Part* part, bool doUndoFlag, bool doCtrls, bool doClones)
       {
-      AudioMsg msg;
-      msg.id = SEQM_REMOVE_EVENT;
-      msg.ev1 = event;
-      msg.p2 = part;
-      msg.a = doCtrls;
-      msg.b = doClones;
-      sendMessage(&msg, doUndoFlag);
+      MusEGlobal::song->applyOperation(UndoOp(UndoOp::DeleteEvent, event,part, doCtrls, doClones), doUndoFlag);
       }
 
 //---------------------------------------------------------
@@ -973,14 +785,7 @@ void Audio::msgDeleteEvent(Event& event, Part* part, bool doUndoFlag, bool doCtr
 
 void Audio::msgChangeEvent(Event& oe, Event& ne, Part* part, bool doUndoFlag, bool doCtrls, bool doClones)
       {
-      AudioMsg msg;
-      msg.id = SEQM_CHANGE_EVENT;
-      msg.ev1 = oe;
-      msg.ev2 = ne;
-      msg.p3 = part;
-      msg.a = doCtrls;
-      msg.b = doClones;
-      sendMessage(&msg, doUndoFlag);
+      MusEGlobal::song->applyOperation(UndoOp(UndoOp::ModifyEvent, ne,oe, part, doCtrls, doClones), doUndoFlag);
       }
 
 //---------------------------------------------------------
@@ -989,11 +794,7 @@ void Audio::msgChangeEvent(Event& oe, Event& ne, Part* part, bool doUndoFlag, bo
 
 void Audio::msgAddTempo(int tick, int tempo, bool doUndoFlag)
       {
-      AudioMsg msg;
-      msg.id = SEQM_ADD_TEMPO;
-      msg.a = tick;
-      msg.b = tempo;
-      sendMessage(&msg, doUndoFlag);
+      MusEGlobal::song->applyOperation(UndoOp(UndoOp::AddTempo, tick, tempo), doUndoFlag);
       }
 
 //---------------------------------------------------------
@@ -1027,11 +828,7 @@ void Audio::msgSetGlobalTempo(int val)
 
 void Audio::msgDeleteTempo(int tick, int tempo, bool doUndoFlag)
       {
-      AudioMsg msg;
-      msg.id = SEQM_REMOVE_TEMPO;
-      msg.a = tick;
-      msg.b = tempo;
-      sendMessage(&msg, doUndoFlag);
+      MusEGlobal::song->applyOperation(UndoOp(UndoOp::DeleteTempo, tick, tempo), doUndoFlag);
       }
 
 //---------------------------------------------------------
@@ -1090,16 +887,6 @@ void Audio::msgRemoveKey(int tick, int key, bool doUndoFlag)
       sendMessage(&msg, doUndoFlag);
       }
 
-//---------------------------------------------------------
-//   msgScanAlsaMidiPorts
-//---------------------------------------------------------
-
-void Audio::msgScanAlsaMidiPorts()
-      {
-      AudioMsg msg;
-      msg.id = SEQM_SCAN_ALSA_MIDI_PORTS;
-      sendMessage(&msg, false);
-      }
 
 //---------------------------------------------------------
 //   msgResetMidiDevices
@@ -1285,32 +1072,6 @@ void Audio::msgSetHwCtrlStates(MidiPort* port, int ch, int ctrl, int val, int la
       }
 
 //---------------------------------------------------------
-//   msgSetTrackOutChannel
-//---------------------------------------------------------
-
-void Audio::msgSetTrackOutChannel(MidiTrack* track, int ch)
-{
-      AudioMsg msg;
-      msg.id = SEQM_SET_TRACK_OUT_CHAN;
-      msg.p1 = track;
-      msg.a = ch;
-      sendMessage(&msg, false);
-}
-
-//---------------------------------------------------------
-//   msgSetTrackOutPort
-//---------------------------------------------------------
-
-void Audio::msgSetTrackOutPort(MidiTrack* track, int port)
-{
-      AudioMsg msg;
-      msg.id = SEQM_SET_TRACK_OUT_PORT;
-      msg.p1 = track;
-      msg.a = port;
-      sendMessage(&msg, false);
-}
-
-//---------------------------------------------------------
 //   msgSetTrackAutomationType
 //---------------------------------------------------------
 
@@ -1324,34 +1085,6 @@ void Audio::msgSetTrackAutomationType(Track* track, int type)
 }
       
 //---------------------------------------------------------
-//   msgRemapPortDrumCtlEvents
-//---------------------------------------------------------
-
-void Audio::msgRemapPortDrumCtlEvents(int mapidx, int newnote, int newchan, int newport)
-{
-      AudioMsg msg;
-      msg.id = SEQM_REMAP_PORT_DRUM_CTL_EVS;
-      msg.ival = mapidx;
-      msg.a = newnote;
-      msg.b = newchan;
-      msg.c = newport;
-      sendMessage(&msg, false);
-}
-
-//---------------------------------------------------------
-//   msgChangeAllPortDrumCtlEvents
-//---------------------------------------------------------
-
-void Audio::msgChangeAllPortDrumCtrlEvents(bool add, bool drumonly)
-{
-      AudioMsg msg;
-      msg.id = SEQM_CHANGE_ALL_PORT_DRUM_CTL_EVS;
-      msg.a = (int)add;
-      msg.b = (int)drumonly;
-      sendMessage(&msg, false);
-}
-
-//---------------------------------------------------------
 //   msgSetSendMetronome
 //---------------------------------------------------------
 
diff --git a/muse2/muse/song.cpp b/muse2/muse/song.cpp
index d13f8398..926ba0ac 100644
--- a/muse2/muse/song.cpp
+++ b/muse2/muse/song.cpp
@@ -216,9 +216,7 @@ Track* Song::addNewTrack(QAction* action, Track* insertAt)
       if((Track::TrackType)n >= Track::AUDIO_SOFTSYNTH)
         return 0;
       
-      Undo operations;
-      Track* t = addTrack(operations, (Track::TrackType)n, insertAt);
-      applyOperationGroup(operations);
+      Track* t = addTrack((Track::TrackType)n, insertAt);
       if (t->isVisible()) {
         deselectTracks();
         t->setSelected(true);
@@ -236,7 +234,7 @@ Track* Song::addNewTrack(QAction* action, Track* insertAt)
 //    If insertAt is valid, inserts before insertAt. Else at the end after all tracks.
 //---------------------------------------------------------
 
-Track* Song::addTrack(Undo& /*operations*/, Track::TrackType type, Track* insertAt)
+Track* Song::addTrack(Track::TrackType type, Track* insertAt)
       {
       Track* track = 0;
       int lastAuxIdx = _auxs.size();
@@ -293,12 +291,9 @@ Track* Song::addTrack(Undo& /*operations*/, Track::TrackType type, Track* insert
       
       int idx = insertAt ? _tracks.index(insertAt) : -1;
       
-      insertTrack1(track, idx);         // this and the below are replaced
-      msgInsertTrack(track, idx, true); // by the UndoOp-operation
-      insertTrack3(track, idx); // does nothing
-      // No, can't do this. insertTrack2 needs to be called now, not later, otherwise it sees
+      // Apply it *now*. insertTrack2 needs to be called now, not later, otherwise it sees
       //  that the track may have routes, and reciprocates them, causing duplicate routes.
-      ///operations.push_back(UndoOp(UndoOp::AddTrack, idx, track));  
+      applyOperation(UndoOp(UndoOp::AddTrack, idx, track));
 
       // Add default track <-> midiport routes. 
       if(track->isMidiTrack()) 
@@ -439,7 +434,8 @@ void Song::duplicateTracks()
   QString track_name;
   int idx;
   int trackno = tl.size();
-  MusEGlobal::song->startUndo();
+  
+  Undo operations;
   for(TrackList::reverse_iterator it = tl.rbegin(); it != tl.rend(); ++it) 
   {
     Track* track = *it;
@@ -449,114 +445,23 @@ void Song::duplicateTracks()
       
       for(int cp = 0; cp < copies; ++cp)
       {
-        // There are two ways to copy a track now. Using the copy constructor or using new + assign(). 
-        // Tested: Both ways seem OK. Prefer copy constructors for simplicity. But new + assign() may be 
-        //  required for fine-grained control over initializing various track types.
-        //
-        
-        //  Set to 0 to use the copy constructor. Set to 1 to use new + assign().
-        // DELETETHIS is this still necessary to keep around?
-        //            also consider removing and adding a hint to a revision number instead
-  #if 0      
-        
-        Track* new_track = 0;
-        int lastAuxIdx = _auxs.size();
-        switch(track->type()) 
-        {
-          case Track::AUDIO_SOFTSYNTH:  // TODO: Handle synths.   p4.0.47
-                // ((AudioTrack*)new_track)->addAuxSend(lastAuxIdx); DELETETHIS?
-                break;
-            
-          case Track::MIDI:
-                new_track = new MidiTrack();
-                new_track->setType(Track::MIDI);
-                break;
-          case Track::DRUM:
-                new_track = new MidiTrack();
-                new_track->setType(Track::DRUM);
-                //((MidiTrack*)new_track)->setOutChannel(9); DELETETHIS?
-                break;
-          case Track::WAVE:
-                new_track = new MusECore::WaveTrack();
-                //((AudioTrack*)new_track)->addAuxSend(lastAuxIdx); DELETETHIS?
-                break;
-          case Track::AUDIO_OUTPUT:
-                new_track = new AudioOutput();
-                break;
-          case Track::AUDIO_GROUP:
-                new_track = new AudioGroup();
-                //((AudioTrack*)new_track)->addAuxSend(lastAuxIdx); DELETETHIS?
-                break;
-          case Track::AUDIO_AUX:
-                new_track = new AudioAux();
-                break;
-          case Track::AUDIO_INPUT:
-                new_track = new AudioInput();
-                //((AudioTrack*)new_track)->addAuxSend(lastAuxIdx); DELETETHIS?
-                break;
-          default:
-                printf("Song::duplicateTracks: Illegal type %d\n", track->type());
-                break;
-        }
-            
-        if(new_track)   
-        {
-          new_track->assign(*track, flags);
-  #else      
-        {
           Track* new_track = track->clone(flags);  
-  #endif
           
           //new_track->setDefaultName(track_name);  // Handled in class now.
 
           idx = trackno + cp;
-          insertTrack1(new_track, idx);         
-          addUndo(MusECore::UndoOp(MusECore::UndoOp::AddTrack, idx, new_track));
-          msgInsertTrack(new_track, idx, false); // No undo.
-          insertTrack3(new_track, idx); 
-        }
+          operations.push_back(MusECore::UndoOp(MusECore::UndoOp::AddTrack, idx, new_track));
       }  
     }
     --trackno;
   }
   
-  MusECore::SongChangedFlags_t update_flags = SC_TRACK_INSERTED;
-  if(flags & (Track::ASSIGN_ROUTES | Track::ASSIGN_DEFAULT_ROUTES))
-    update_flags |= SC_ROUTE;
-  MusEGlobal::song->endUndo(update_flags);
+  MusEGlobal::song->applyOperationGroup(operations);
   MusEGlobal::audio->msgUpdateSoloStates();
 }          
       
-//---------------------------------------------------------
-//   cmdRemoveTrack
-//---------------------------------------------------------
 
-void Song::cmdRemoveTrack(Track* track)
-      {
-      int idx = _tracks.index(track);
-      addUndo(UndoOp(UndoOp::DeleteTrack, idx, track));
-      removeTrack2(track);
-      updateFlags |= SC_TRACK_REMOVED;
-      }
 
-//---------------------------------------------------------
-//   removeMarkedTracks
-//---------------------------------------------------------
-
-void Song::removeMarkedTracks()
-      {
-      bool loop;
-      do {
-            loop = false;
-            for (iTrack t = _tracks.begin(); t != _tracks.end(); ++t) {
-                  if ((*t)->selected()) {
-                        removeTrack2(*t);
-                        loop = true;
-                        break;
-                        }
-                  }
-            } while (loop);
-      }
 
 //---------------------------------------------------------
 //   deselectTracks
@@ -577,15 +482,15 @@ bool Song::addEvent(Event& event, Part* part)
       {
       // Return false if the event is already found. 
       // (But allow a port controller value, above, in case it is not already stored.)
-      if(part->events()->find(event) != part->events()->end())
+      if(part->events().find(event) != part->events().end())
       {
         // This can be normal for some (redundant) operations.
         if(MusEGlobal::debugMsg)
-          printf("Song::addEvent event already found in part:%s size:%zd\n", part->name().toLatin1().constData(), part->events()->size());
+          printf("Song::addEvent event already found in part:%s size:%zd\n", part->name().toLatin1().constData(), part->events().size());
         return false;
       }
       
-      part->events()->add(event);
+      part->nonconst_events().add(event);
       return true;
       }
 
@@ -595,18 +500,18 @@ bool Song::addEvent(Event& event, Part* part)
 
 void Song::changeEvent(Event& oldEvent, Event& newEvent, Part* part)
 {
-      iEvent i = part->events()->find(oldEvent);
+      iEvent i = part->nonconst_events().find(oldEvent);
       
-      if (i == part->events()->end()) {
+      if (i == part->nonconst_events().end()) {
             // This can be normal for some (redundant) operations.
             if(MusEGlobal::debugMsg)
-              printf("Song::changeEvent event not found in part:%s size:%zd\n", part->name().toLatin1().constData(), part->events()->size());
+              printf("Song::changeEvent event not found in part:%s size:%zd\n", part->name().toLatin1().constData(), part->nonconst_events().size());
             // no "return;" because: Allow it to add the new event.  (And remove the old one from the midi port controller!) (tim)
             }
       else
-        part->events()->erase(i);
+        part->nonconst_events().erase(i);
         
-      part->events()->add(newEvent);
+      part->nonconst_events().add(newEvent);
 }
 
 //---------------------------------------------------------
@@ -615,14 +520,14 @@ void Song::changeEvent(Event& oldEvent, Event& newEvent, Part* part)
 
 void Song::deleteEvent(Event& event, Part* part)
       {
-      iEvent ev = part->events()->find(event);
-      if (ev == part->events()->end()) {
+      iEvent ev = part->nonconst_events().find(event);
+      if (ev == part->nonconst_events().end()) {
             // This can be normal for some (redundant) operations.
             if(MusEGlobal::debugMsg)
-              printf("Song::deleteEvent event not found in part:%s size:%zd\n", part->name().toLatin1().constData(), part->events()->size());
+              printf("Song::deleteEvent event not found in part:%s size:%zd\n", part->name().toLatin1().constData(), part->nonconst_events().size());
             return;
             }
-      part->events()->erase(ev);
+      part->nonconst_events().erase(ev);
       }
 
 //---------------------------------------------------------
@@ -646,8 +551,8 @@ void Song::remapPortDrumCtrlEvents(int mapidx, int newnote, int newchan, int new
     for(ciPart ip = pl->begin(); ip != pl->end(); ++ip) 
     {
       MidiPart* part = (MidiPart*)(ip->second);
-      const EventList* el = part->cevents();
-      for(ciEvent ie = el->begin(); ie != el->end(); ++ie)
+      const EventList& el = part->events();
+      for(ciEvent ie = el.begin(); ie != el.end(); ++ie)
       {
         const Event& ev = ie->second;
         if(ev.type() != Controller)
@@ -717,17 +622,10 @@ void Song::changeAllPortDrumCtrlEvents(bool add, bool drumonly)
     for(ciPart ip = pl->begin(); ip != pl->end(); ++ip) 
     {
       MidiPart* part = (MidiPart*)(ip->second);
-      const EventList* el = part->cevents();
-      // unsigned len = part->lenTick(); // Commented out by flo, see below
-      for(ciEvent ie = el->begin(); ie != el->end(); ++ie)
+      for(ciEvent ie = part->events().begin(); ie != part->events().end(); ++ie)
       {
         const Event& ev = ie->second;
-        // Added by T356. Do not handle events which are past the end of the part.
-        // Commented out by flo: yes, DO handle them! these are "hidden events"
-        //                       which may be revealed later again!
-        // if(ev.tick() >= len)
-        //   break;
-                    
+
         if(ev.type() != Controller)
           continue;
           
@@ -765,45 +663,35 @@ void Song::changeAllPortDrumCtrlEvents(bool add, bool drumonly)
   }
 }
 
-void Song::addACEvent(AudioTrack* t, int acid, int frame, double val)
-{
-  MusEGlobal::audio->msgAddACEvent(t, acid, frame, val);
-}
-
-void Song::changeACEvent(AudioTrack* t, int acid, int frame, int newFrame, double val)
-{
-  MusEGlobal::audio->msgChangeACEvent(t, acid, frame, newFrame, val);
-}
-
 //---------------------------------------------------------
 //   cmdAddRecordedEvents
 //    add recorded Events into part
 //---------------------------------------------------------
 
-void Song::cmdAddRecordedEvents(MidiTrack* mt, EventList* events, unsigned startTick)
+void Song::cmdAddRecordedEvents(MidiTrack* mt, const EventList& events, unsigned startTick)
       {
-      if (events->empty()) {
+      if (events.empty()) {
             if (MusEGlobal::debugMsg)
                   printf("no events recorded\n");
             return;
             }
-      iEvent s;
-      iEvent e;
+      ciEvent s;
+      ciEvent e;
       unsigned endTick;
 
       if((MusEGlobal::audio->loopCount() > 0 && startTick > lPos().tick()) || (punchin() && startTick < lPos().tick()))
       {
             startTick = lpos();
-            s = events->lower_bound(startTick);
+            s = events.lower_bound(startTick);
       }
       else 
       {
-            s = events->begin();
+            s = events.begin();
       }
       
       // search for last noteOff:
       endTick = 0;
-      for (iEvent i = events->begin(); i != events->end(); ++i) {
+      for (ciEvent i = events.begin(); i != events.end(); ++i) {
             Event ev   = i->second;
             unsigned l = ev.endTick();
             if (l > endTick)
@@ -813,10 +701,10 @@ void Song::cmdAddRecordedEvents(MidiTrack* mt, EventList* events, unsigned start
       if((MusEGlobal::audio->loopCount() > 0) || (punchout() && endTick > rPos().tick()) )
       {
             endTick = rpos();
-            e = events->lower_bound(endTick);
+            e = events.lower_bound(endTick);
       }
       else
-            e = events->end();
+            e = events.end();
 
       if (startTick > endTick) {
             if (MusEGlobal::debugMsg)
@@ -832,7 +720,7 @@ void Song::cmdAddRecordedEvents(MidiTrack* mt, EventList* events, unsigned start
       //---------------------------------------------------
 
       PartList* pl = mt->parts();
-      MidiPart* part = 0;
+      const MidiPart* part = 0;
       iPart ip;
       for (ip = pl->begin(); ip != pl->end(); ++ip) {
             part = (MidiPart*)(ip->second);
@@ -845,39 +733,42 @@ void Song::cmdAddRecordedEvents(MidiTrack* mt, EventList* events, unsigned start
             if (MusEGlobal::debugMsg)
                   printf("create new part for recorded events\n");
             // create new part
-            part      = new MidiPart(mt);
+            MidiPart* newpart;
+            newpart      = new MidiPart(mt);
             
             // Round the start down using the Arranger part snap raster value. 
             startTick = AL::sigmap.raster1(startTick, arrangerRaster());
             // Round the end up using the Arranger part snap raster value. 
             endTick   = AL::sigmap.raster2(endTick, arrangerRaster());
             
-            part->setTick(startTick);
-            part->setLenTick(endTick - startTick);
-            part->setName(mt->name());
+            newpart->setTick(startTick);
+            newpart->setLenTick(endTick - startTick);
+            newpart->setName(mt->name());
             // copy events
-            for (iEvent i = s; i != e; ++i) {
-                  Event old = i->second;
+            for (ciEvent i = s; i != e; ++i) {
+                  const Event& old = i->second;
                   Event event = old.clone();
                   event.setTick(old.tick() - startTick);
                   // addEvent also adds port controller values. So does msgAddPart, below. Let msgAddPart handle them.
                   //addEvent(event, part);
-                  if(part->events()->find(event) == part->events()->end())
-                    part->events()->add(event);
+                  if(newpart->events().find(event) == newpart->events().end())
+                    newpart->nonconst_events().add(event);
                   }
-            MusEGlobal::audio->msgAddPart(part);
+            MusEGlobal::audio->msgAddPart(newpart);
             updateFlags |= SC_PART_INSERTED;
             return;
             }
 
       updateFlags |= SC_EVENT_INSERTED;
 
+      Undo operations;
+
       unsigned partTick = part->tick();
       if (endTick > part->endTick()) {
             // Determine new part length...
             endTick = 0;
-            for (iEvent i = s; i != e; ++i) {
-                  Event event = i->second;
+            for (ciEvent i = s; i != e; ++i) {
+                  const Event& event = i->second;
                   unsigned tick = event.tick() - partTick + event.lenTick();
                   if (endTick < tick)
                         endTick = tick;
@@ -886,88 +777,31 @@ void Song::cmdAddRecordedEvents(MidiTrack* mt, EventList* events, unsigned start
             // Round the end up (again) using the Arranger part snap raster value. 
             endTick   = AL::sigmap.raster2(endTick, arrangerRaster());
             
-            
-            removePortCtrlEvents(part, false); // Remove all of the part's port controller values. Don't do clone parts.
-
-            // Clone the part. This doesn't increment aref count, and doesn't chain clones.
-            // It also gives the new part a new serial number, but it is 
-            //  overwritten with the old one by Song::changePart(), below. 
-            Part* newPart = part->clone();
-            
-            newPart->setLenTick(endTick);  // Set the new part's length.
-            changePart(part, newPart);     // Change the part.
-            
-            part->events()->incARef(-1);   // Manually adjust reference counts. HACK!
-            newPart->events()->incARef(1);
-            
-            replaceClone(part, newPart);   // Replace the part in the clone chain with the new part.
-            
-            // Now add all of the new part's port controller values. Indicate do not do clone parts.
-            addPortCtrlEvents(newPart, false);
-            
             // Create an undo op. Indicate do port controller values but not clone parts. 
-            addUndo(UndoOp(UndoOp::ModifyPart, part, newPart, true, false));
+            operations.push_back(UndoOp(UndoOp::ModifyPartLength, part, part->lenTick(), endTick, true, false)); // FIXME XTICKS! FINDMICHJETZT!
             updateFlags |= SC_PART_MODIFIED;
+      }
             
-            if (_recMode == REC_REPLACE)
-            {
-                  iEvent si = newPart->events()->lower_bound(startTick - newPart->tick());
-                  iEvent ei = newPart->events()->lower_bound(newPart->endTick() - newPart->tick());
-                  for (iEvent i = si; i != ei; ++i) 
-                  {
-                    Event event = i->second;
-                    // Indicate do port controller values and clone parts. 
-                    addUndo(UndoOp(UndoOp::DeleteEvent, event, newPart, true, true));
-                    // Remove the event from the new part's port controller values, and do all clone parts.
-                    removePortCtrlEvents(event, newPart, true);
-                  }
-                  newPart->events()->erase(si, ei);
-            }
-            
-            for (iEvent i = s; i != e; ++i) {
-                  Event event = i->second;
-                  event.setTick(event.tick() - partTick);
-                  Event e;
-                  // Create an undo op. Indicate do port controller values and clone parts. 
-                  addUndo(UndoOp(UndoOp::AddEvent, e, event, newPart, true, true));
-                  
-                  if(newPart->events()->find(event) == newPart->events()->end())
-                    newPart->events()->add(event);
-                  
-                  // Add the event to the new part's port controller values, and do all clone parts.
-                  addPortCtrlEvents(event, newPart, true);
-                  }
-            }
-      else {
-            if (_recMode == REC_REPLACE) {
-                  iEvent si = part->events()->lower_bound(startTick - part->tick());
-                  iEvent ei = part->events()->lower_bound(endTick   - part->tick());
-
-                  for (iEvent i = si; i != ei; ++i) {
-                        Event event = i->second;
-                        // Indicate that controller values and clone parts were handled.
-                        addUndo(UndoOp(UndoOp::DeleteEvent, event, part, true, true));
-                        // Remove the event from the part's port controller values, and do all clone parts.
-                        removePortCtrlEvents(event, part, true);
-                        }
-                  part->events()->erase(si, ei);
-                  }
-            for (iEvent i = s; i != e; ++i) {
-                  Event event = i->second;
-                  int tick = event.tick() - partTick;
-                  event.setTick(tick);
-                  
+
+      if (_recMode == REC_REPLACE) {
+            ciEvent si = part->events().lower_bound(startTick - part->tick());
+            ciEvent ei = part->events().lower_bound(endTick   - part->tick());
+
+            for (ciEvent i = si; i != ei; ++i) {
+                  const Event& event = i->second;
                   // Indicate that controller values and clone parts were handled.
-                  addUndo(UndoOp(UndoOp::AddEvent, event, part, true, true));
-                  
-                  if(part->events()->find(event) == part->events()->end())
-                    part->events()->add(event);
-                  
-                  // Add the event to the part's port controller values, and do all clone parts.
-                  addPortCtrlEvents(event, part, true);
-                  }
+                  operations.push_back(UndoOp(UndoOp::DeleteEvent, event, part, true, true));
             }
       }
+      for (ciEvent i = s; i != e; ++i) {
+            Event event = i->second.clone();
+            event.setTick(event.tick() - partTick);
+            // Indicate that controller values and clone parts were handled.
+            operations.push_back(UndoOp(UndoOp::AddEvent, event, part, true, true));
+      }
+      
+      applyOperationGroup(operations,false); // don't do undo, startUndo must have been called from outside.
+}
 
 //---------------------------------------------------------
 //   findTrack
@@ -1400,23 +1234,6 @@ void Song::updatePos()
       }
 
 //---------------------------------------------------------
-//   setChannelMute
-//    mute all midi tracks associated with channel
-//---------------------------------------------------------
-
-void Song::setChannelMute(int channel, bool val)
-      {
-      for (iTrack i = _tracks.begin(); i != _tracks.end(); ++i) {
-            MidiTrack* track = dynamic_cast<MidiTrack*>(*i);
-            if (track == 0)
-                  continue;
-            if (track->outChannel() == channel)
-                  track->setMute(val);
-            }
-      emit songChanged(SC_MUTE);
-      }
-
-//---------------------------------------------------------
 //   len
 //---------------------------------------------------------
 
@@ -1788,10 +1605,17 @@ void Song::endMsgCmd()
 void Song::undo()
       {
       updateFlags = 0;
-      if (doUndo1())
+      
+      Undo& opGroup = undoList->back();
+      
+      if (opGroup.empty())
             return;
-      MusEGlobal::audio->msgUndo();
-      doUndo3();
+      
+      MusEGlobal::audio->msgRevertOperationGroup(opGroup);
+      
+      redoList->push_back(opGroup);
+      undoList->pop_back();
+      
       MusEGlobal::redoAction->setEnabled(true);
       MusEGlobal::undoAction->setEnabled(!undoList->empty());
       setUndoRedoText();
@@ -1800,6 +1624,7 @@ void Song::undo()
         MusEGlobal::audio->msgUpdateSoloStates();
 
       emit songChanged(updateFlags);
+      emit sigDirty();
       }
 
 //---------------------------------------------------------
@@ -1809,10 +1634,17 @@ void Song::undo()
 void Song::redo()
       {
       updateFlags = 0;
-      if (doRedo1())
+
+      Undo& opGroup = redoList->back();
+      
+      if (opGroup.empty())
             return;
-      MusEGlobal::audio->msgRedo();
-      doRedo3();
+      
+      MusEGlobal::audio->msgExecuteOperationGroup(opGroup);
+      
+      undoList->push_back(opGroup);
+      redoList->pop_back();
+      
       MusEGlobal::undoAction->setEnabled(true);
       MusEGlobal::redoAction->setEnabled(!redoList->empty());
       setUndoRedoText();
@@ -1821,6 +1653,7 @@ void Song::redo()
         MusEGlobal::audio->msgUpdateSoloStates();
 
       emit songChanged(updateFlags);
+      emit sigDirty();
       }
 
 //---------------------------------------------------------
@@ -1834,78 +1667,14 @@ void Song::processMsg(AudioMsg* msg)
             case SEQM_UPDATE_SOLO_STATES:
                   updateSoloStates();
                   break;
-            case SEQM_UNDO:
-                  doUndo2();
-                  break;
-            case SEQM_REDO:
-                  doRedo2();
-                  break;
-            case SEQM_MOVE_TRACK:
-                  if (msg->a > msg->b) {
-                        for (int i = msg->a; i > msg->b; --i) {
-                              swapTracks(i, i-1);
-                              }
-                        }
-                  else {
-                        for (int i = msg->a; i < msg->b; ++i) {
-                              swapTracks(i, i+1);
-                              }
-                        }
-                  updateFlags = SC_TRACK_MODIFIED;
-                  break;
-            case SEQM_ADD_EVENT:
-                  updateFlags = SC_EVENT_INSERTED;
-                  if (addEvent(msg->ev1, (MidiPart*)msg->p2)) {
-                        Event ev;
-                        addUndo(UndoOp(UndoOp::AddEvent, ev, msg->ev1, (Part*)msg->p2, msg->a, msg->b));
-                        }
-                  else
-                        updateFlags = 0;
-                  if(msg->a)
-                    addPortCtrlEvents(msg->ev1, (Part*)msg->p2, msg->b);
+            case SEQM_EXECUTE_OPERATION_GROUP:
+                  executeOperationGroup2(*msg->operations);
                   break;
-            case SEQM_REMOVE_EVENT:
-                  {
-                  Event event = msg->ev1;
-                  MidiPart* part = (MidiPart*)msg->p2;
-                  if(msg->a)
-                    removePortCtrlEvents(event, part, msg->b);
-                  Event e;
-                  addUndo(UndoOp(UndoOp::DeleteEvent, e, event, (Part*)part, msg->a, msg->b));
-                  deleteEvent(event, part);
-                  updateFlags = SC_EVENT_REMOVED;
-                  }
-                  break;
-            case SEQM_CHANGE_EVENT:
-                  if(msg->a)
-                    removePortCtrlEvents(msg->ev1, (MidiPart*)msg->p3, msg->b);
-                  changeEvent(msg->ev1, msg->ev2, (MidiPart*)msg->p3);
-                  if(msg->a)
-                    addPortCtrlEvents(msg->ev2, (Part*)msg->p3, msg->b);
-                  addUndo(UndoOp(UndoOp::ModifyEvent, msg->ev2, msg->ev1, (Part*)msg->p3, msg->a, msg->b));
-                  updateFlags = SC_EVENT_MODIFIED;
-                  break;
-            
-            // Moved here from MidiSeq::processMsg   p4.0.34
-            case SEQM_ADD_TRACK:
-                  insertTrack2(msg->track, msg->ival);
-                  break;
-            case SEQM_REMOVE_TRACK:
-                  cmdRemoveTrack(msg->track);
-                  break;
-            //case SEQM_CHANGE_TRACK:     DELETETHIS 3
-            //      changeTrack((Track*)(msg->p1), (Track*)(msg->p2));
-            //      break;
-            case SEQM_ADD_PART:
-                  cmdAddPart((Part*)msg->p1);
-                  break;
-            case SEQM_REMOVE_PART:
-                  cmdRemovePart((Part*)msg->p1);
-                  break;
-            case SEQM_CHANGE_PART:
-                  cmdChangePart((Part*)msg->p1, (Part*)msg->p2, msg->a, msg->b);
+            case SEQM_REVERT_OPERATION_GROUP:
+                  revertOperationGroup2(*msg->operations);
                   break;
             
+
             case SEQM_ADD_TEMPO:
                   addUndo(UndoOp(UndoOp::AddTempo, msg->a, msg->b));
                   MusEGlobal::tempomap.addTempo(msg->a, msg->b);
@@ -1959,56 +1728,6 @@ void Song::processMsg(AudioMsg* msg)
       }
 
 //---------------------------------------------------------
-//   cmdAddPart
-//---------------------------------------------------------
-
-void Song::cmdAddPart(Part* part)
-      {
-      addPart(part);
-      addUndo(UndoOp(UndoOp::AddPart, part));
-      updateFlags = SC_PART_INSERTED;
-      }
-
-//---------------------------------------------------------
-//   cmdRemovePart
-//---------------------------------------------------------
-
-void Song::cmdRemovePart(Part* part)
-      {
-      removePart(part);
-      addUndo(UndoOp(UndoOp::DeletePart, part));
-      part->events()->incARef(-1);
-      unchainClone(part);
-      updateFlags = SC_PART_REMOVED;
-      }
-
-//---------------------------------------------------------
-//   cmdChangePart
-//---------------------------------------------------------
-
-void Song::cmdChangePart(Part* oldPart, Part* newPart, bool doCtrls, bool doClones)
-      {
-      if(doCtrls)
-        removePortCtrlEvents(oldPart, doClones);
-      
-      changePart(oldPart, newPart);
-      
-      addUndo(UndoOp(UndoOp::ModifyPart, oldPart, newPart, doCtrls, doClones));
-      
-      // Changed by T356. Do not decrement ref count if the new part is a clone of the old part, since the event list
-      //  will still be active.
-      if(oldPart->cevents() != newPart->cevents())
-        oldPart->events()->incARef(-1);
-      
-      replaceClone(oldPart, newPart);
-
-      if(doCtrls)
-        addPortCtrlEvents(newPart, doClones);
-      
-      updateFlags = SC_PART_MODIFIED;
-      }
-
-//---------------------------------------------------------
 //   panic
 //---------------------------------------------------------
 
@@ -2383,7 +2102,7 @@ void Song::recordEvent(MidiTrack* mt, Event& event)
 
       unsigned tick  = event.tick();
       PartList* pl   = mt->parts();
-      MidiPart* part = 0;
+      const MidiPart* part = 0;
       iPart ip;
       for (ip = pl->begin(); ip != pl->end(); ++ip) {
             part = (MidiPart*)(ip->second);
@@ -2395,14 +2114,14 @@ void Song::recordEvent(MidiTrack* mt, Event& event)
       updateFlags |= SC_EVENT_INSERTED;
       if (ip == pl->end()) {
             // create new part
-            part          = new MidiPart(mt);
+            MidiPart* part = new MidiPart(mt);
             int startTick = roundDownBar(tick);
             int endTick   = roundUpBar(tick + 1);
             part->setTick(startTick);
             part->setLenTick(endTick - startTick);
             part->setName(mt->name());
             event.move(-startTick);
-            part->events()->add(event);
+            part->nonconst_events().add(event);
             MusEGlobal::audio->msgAddPart(part);
             return;
             }
@@ -2413,23 +2132,21 @@ void Song::recordEvent(MidiTrack* mt, Event& event)
       Event ev;
       if(event.type() == Controller)
       {
-        EventRange range = part->events()->equal_range(tick);
-        for(iEvent i = range.first; i != range.second; ++i) 
+        EventRange range = part->events().equal_range(tick);
+        for(ciEvent i = range.first; i != range.second; ++i) 
         {
           ev = i->second;
           if(ev.type() == Controller && ev.dataA() == event.dataA())
           {
             if(ev.dataB() == event.dataB()) // Don't bother if already set.
               return;
-            // Indicate do undo, and do port controller values and clone parts. 
-            MusEGlobal::audio->msgChangeEvent(ev, event, part, true, true, true);
+            MusEGlobal::song->applyOperation(UndoOp(UndoOp::ModifyEvent,event,ev,part,true,true));
             return;
           }
         }
       }  
       
-      // Indicate do undo, and do port controller values and clone parts. 
-      MusEGlobal::audio->msgAddEvent(event, part, true, true, true);
+      MusEGlobal::song->applyOperation(UndoOp(UndoOp::AddEvent, event, part, true,true));
       }
 
 //---------------------------------------------------------
@@ -2705,8 +2422,8 @@ int Song::execMidiAutomationCtlPopup(MidiTrack* track, MidiPart* part, const QPo
     unsigned partEnd   = partStart + part->lenTick();
     if(tick >= partStart && tick < partEnd)
     {
-      EventRange range = part->events()->equal_range(tick - partStart);
-      for(iEvent i = range.first; i != range.second; ++i) 
+      EventRange range = part->events().equal_range(tick - partStart);
+      for(ciEvent i = range.first; i != range.second; ++i) 
       {
         ev = i->second;
         if(ev.type() == Controller)
@@ -2785,7 +2502,7 @@ int Song::execMidiAutomationCtlPopup(MidiTrack* track, MidiPart* part, const QPo
               part->setLenTick(endTick - startTick);
               part->setName(mt->name());
               e.setTick(tick - startTick);
-              part->events()->add(e);
+              part->nonconst_events().add(e);
               // Allow undo.
               MusEGlobal::audio->msgAddPart(part);
             }
@@ -3040,7 +2757,7 @@ void Song::connectJackRoutes(AudioTrack* track, bool disconnect)
 void Song::insertTrack0(Track* track, int idx)
       {
       insertTrack1(track, idx);
-      insertTrack2(track, idx);  // MusEGlobal::audio->msgInsertTrack(track, idx, false); DELETETHIS or is this somehow explanatory?
+      insertTrack2(track, idx);  // the same as MusEGlobal::audio->msgInsertTrack(track, idx, false);
       insertTrack3(track, idx);
       }
 
@@ -3221,18 +2938,6 @@ void Song::insertTrack3(Track* /*track*/, int /*idx*/)//prevent compiler warning
 }
 
 //---------------------------------------------------------
-//   removeTrack0
-//---------------------------------------------------------
-
-void Song::removeTrack0(Track* track)
-      {
-      removeTrack1(track);
-      MusEGlobal::audio->msgRemoveTrack(track);
-      removeTrack3(track);
-      update(SC_TRACK_REMOVED);
-      }
-
-//---------------------------------------------------------
 //   removeTrack1
 //    non realtime part of removeTrack
 //---------------------------------------------------------
@@ -3285,12 +2990,12 @@ void Song::removeTrack2(Track* track)
             case Track::DRUM:
             case Track::NEW_DRUM:
                   removePortCtrlEvents(((MidiTrack*)track));
-                  unchainTrackParts(track, true);
+                  unchainTrackParts(track);
                   
                   _midis.erase(track);
                   break;
             case Track::WAVE:
-                  unchainTrackParts(track, true);
+                  unchainTrackParts(track);
                   
                   _waves.erase(track);
                   break;
@@ -3439,7 +3144,7 @@ void Song::executeScript(const char* scriptfile, PartList* parts, int quant, boo
             fprintf(fp, "BEATLEN %d\n", AL::sigmap.ticksBeat(0));
             fprintf(fp, "QUANTLEN %d\n", quant);
 
-            for (iEvent e = part->events()->begin(); e != part->events()->end(); e++) {
+            for (ciEvent e = part->events().begin(); e != part->events().end(); e++) {
                 Event ev = e->second;
 
                 if (ev.isNote())
@@ -3583,14 +3288,14 @@ QString Song::getScriptPath(int id, bool isdelivered)
       return path;
 }
 
-void Song::informAboutNewParts(const std::map< Part*, std::set<Part*> >& param)
+void Song::informAboutNewParts(const std::map< const Part*, std::set<const Part*> >& param)
 {
   emit newPartsCreated(param);
 }
 
-void Song::informAboutNewParts(Part* orig, Part* p1, Part* p2, Part* p3, Part* p4, Part* p5, Part* p6, Part* p7, Part* p8, Part* p9)
+void Song::informAboutNewParts(const Part* orig, const Part* p1, const Part* p2, const Part* p3, const Part* p4, const Part* p5, const Part* p6, const Part* p7, const Part* p8, const Part* p9)
 {
-  std::map< Part*, std::set<Part*> > temp;
+  std::map<const Part*, std::set<const Part*> > temp;
   
   temp[orig].insert(p1);
   temp[orig].insert(p2);
@@ -3601,7 +3306,7 @@ void Song::informAboutNewParts(Part* orig, Part* p1, Part* p2, Part* p3, Part* p
   temp[orig].insert(p7);
   temp[orig].insert(p8);
   temp[orig].insert(p9);
-  temp[orig].erase(static_cast<Part*>(NULL));
+  temp[orig].erase(static_cast<const Part*>(NULL));
   temp[orig].erase(orig);
   
   informAboutNewParts(temp);
diff --git a/muse2/muse/song.h b/muse2/muse/song.h
index 6621de35..a25f1d55 100644
--- a/muse2/muse/song.h
+++ b/muse2/muse/song.h
@@ -171,9 +171,27 @@ class Song : public QObject {
       Song(const char* name = 0);
       ~Song();
 
-      bool applyOperationGroup(Undo& group, bool doUndo=true);
-      void informAboutNewParts(const std::map< Part*, std::set<Part*> >&);
-      void informAboutNewParts(Part* orig, Part* p1, Part* p2=NULL, Part* p3=NULL, Part* p4=NULL, Part* p5=NULL, Part* p6=NULL, Part* p7=NULL, Part* p8=NULL, Part* p9=NULL);
+      /** It is not allowed nor checked(!) to AddPart a clone, and
+       *  to AddEvent/DeleteEvent/ModifyEvent/SelectEvent events which
+       *  would need to be replicated to the newly added clone part!
+       */
+      bool applyOperationGroup(Undo& group, bool doUndo=true); // group may be changed! prepareOperationGroup is called on group!
+      bool applyOperation(const UndoOp& op, bool doUndo=true);
+      
+      /** this sends emits a signal to each MidiEditor or whoever is interested.
+       *  For each part which is 1) opened in this MidiEditor and 2) which is
+       *  a key in this map, the Editors shall no more edit this part, but instead
+       *  all parts in the_map[old_part] (which is a std::set<Part*>)
+       */
+      void informAboutNewParts(const std::map< const Part*, std::set<const Part*> >&);
+      /** this sends emits a signal to each MidiEditor or whoever is interested.
+       *  For each part which is 1) opened in this MidiEditor and 2) which is
+       *  a key in this map, the Editors shall no more edit this part, but instead
+       *  all parts in the_map[old_part] (which is a std::set<Part*>)
+       *  this is a special case of the general function, which only replaces one part
+       *  by up to nine different.
+       */
+      void informAboutNewParts(const Part* orig, const Part* p1, const Part* p2=NULL, const Part* p3=NULL, const Part* p4=NULL, const Part* p5=NULL, const Part* p6=NULL, const Part* p7=NULL, const Part* p8=NULL, const Part* p9=NULL);
 
       void putEvent(int pv);
       void endMsgCmd();
@@ -263,36 +281,29 @@ class Song : public QObject {
       //-----------------------------------------
 
       void cmdAddRecordedWave(WaveTrack* track, Pos, Pos);  
-      void cmdAddRecordedEvents(MidiTrack*, EventList*, unsigned);
-      bool addEvent(Event&, Part*);
-      void changeEvent(Event&, Event&, Part*);
-      void deleteEvent(Event&, Part*);
-      void cmdChangeWave(QString original, QString tmpfile, unsigned sx, unsigned ex);
-      void remapPortDrumCtrlEvents(int mapidx, int newnote, int newchan, int newport);
-      void changeAllPortDrumCtrlEvents(bool add, bool drumonly = false);
+      void cmdAddRecordedEvents(MidiTrack*, const EventList&, unsigned);
+      bool addEvent(Event&, Part*);                 // only called from audio thread. FIXME TODO: move functionality into undo.cpp
+      void changeEvent(Event&, Event&, Part*);      // only called from audio thread. FIXME TODO: move functionality into undo.cpp
+      void deleteEvent(Event&, Part*);              // only called from audio thread. FIXME TODO: move functionality into undo.cpp
+      void cmdChangeWave(QString original, QString tmpfile, unsigned sx, unsigned ex); // FIXME TODO broken, fix that.
+      void remapPortDrumCtrlEvents(int mapidx, int newnote, int newchan, int newport); // called from GUI thread
+      void changeAllPortDrumCtrlEvents(bool add, bool drumonly = false); // called from GUI thread
       
-      void addACEvent(AudioTrack* t, int acid, int frame, double val);
-      void changeACEvent(AudioTrack* t, int acid, int frame, int newFrame, double val);
       void addExternalTempo(const TempoRecEvent& e) { _tempoFifo.put(e); }
       
       //-----------------------------------------
       //   part manipulations
       //-----------------------------------------
 
-      void cmdResizePart(Track* t, Part* p, unsigned int size, bool doClones=false);
-      void cmdSplitPart(Track* t, Part* p, int tick);
-      void cmdGluePart(Track* t, Part* p);
+      void cmdResizePart(Track* t, Part* p, unsigned int size, bool doClones=false); // called from GUI thread, calls applyOperationGroup. FIXME TODO: better move that into functions.cpp or whatever.
 
       void addPart(Part* part);
       void removePart(Part* part);
-      void changePart(Part*, Part*);
-      PartList* getSelectedMidiParts() const;
+
+      
+      PartList* getSelectedMidiParts() const; // FIXME TODO move functionality into function.cpp
       PartList* getSelectedWaveParts() const;
-      bool msgRemoveParts();
 
-      void cmdChangePart(Part* oldPart, Part* newPart, bool doCtrls, bool doClones);
-      void cmdRemovePart(Part* part);
-      void cmdAddPart(Part* part);
       int arrangerRaster() { return _arrangerRaster; }        // Used by Song::cmdAddRecordedWave to snap new wave parts
       void setArrangerRaster(int r) { _arrangerRaster = r; }  // Used by Arranger snap combo box
 
@@ -309,17 +320,12 @@ class Song : public QObject {
       AuxList* auxs()           { return &_auxs;    }
       SynthIList* syntis()      { return &_synthIs; }
       
-      void cmdRemoveTrack(Track* track);
-      void removeTrack0(Track* track);
       void removeTrack1(Track* track);
       void removeTrack2(Track* track);
       void removeTrack3(Track* track);
-      void removeMarkedTracks();
-      //void changeTrack(Track* oldTrack, Track* newTrack); DELETETHIS
       MidiTrack* findTrack(const Part* part) const;
       Track* findTrack(const QString& name) const;
       void swapTracks(int i1, int i2);
-      void setChannelMute(int channel, bool flag);
       void setRecordFlag(Track*, bool);
       void insertTrack0(Track*, int idx);
       void insertTrack1(Track*, int idx);
@@ -328,7 +334,6 @@ class Song : public QObject {
       void deselectTracks();
       void readRoute(Xml& xml);
       void recordEvent(MidiTrack*, Event&);
-      void msgInsertTrack(Track* track, int idx, bool u = true);
       // Enable all track and plugin controllers, and synth controllers if applicable, which are NOT in AUTO_WRITE mode.
       void reenableTouchedControllers();  
       void clearRecAutomation(bool clearList);
@@ -340,20 +345,20 @@ class Song : public QObject {
       void updateSoloStates();
 
       //-----------------------------------------
-      //   undo, redo
+      //   undo, redo, operation groups
       //-----------------------------------------
 
       void startUndo();
       void endUndo(MusECore::SongChangedFlags_t);
 
-      void undoOp(UndoOp::UndoType type, const char* changedFile, const char* changeData, int startframe, int endframe);
+	  void undoOp(UndoOp::UndoType type, const char* changedFile, const char* changeData, int startframe, int endframe); // FIXME FINDMICHJETZT what's that?! remove it!
 
-      bool doUndo1();
-      void doUndo2();
-      void doUndo3();
-      bool doRedo1();
-      void doRedo2();
-      void doRedo3();
+      void executeOperationGroup1(Undo& operations);
+      void executeOperationGroup2(Undo& operations);
+      void executeOperationGroup3(Undo& operations);
+      void revertOperationGroup1(Undo& operations);
+      void revertOperationGroup2(Undo& operations);
+      void revertOperationGroup3(Undo& operations);
 
       void addUndo(UndoOp i);
       void setUndoRedoText();
@@ -412,7 +417,7 @@ class Song : public QObject {
       void setQuantize(bool val);
       void panic();
       void seqSignal(int fd);
-      Track* addTrack(Undo& operations, Track::TrackType type, Track* insertAt = 0);
+      Track* addTrack(Track::TrackType type, Track* insertAt = 0);
       Track* addNewTrack(QAction* action, Track* insertAt = 0);
       void duplicateTracks();
       QString getScriptPath(int id, bool delivered);
@@ -432,7 +437,7 @@ class Song : public QObject {
       void midiPortsChanged();
       void midiNote(int pitch, int velo);  
       void controllerChanged(MusECore::Track*, int); 
-      void newPartsCreated(const std::map< MusECore::Part*, std::set<MusECore::Part*> >&);
+      void newPartsCreated(const std::map< const MusECore::Part*, std::set<const MusECore::Part*> >&);
       void sigDirty();
       };
 
diff --git a/muse2/muse/songfile.cpp b/muse2/muse/songfile.cpp
index b07d1243..78338bac 100644
--- a/muse2/muse/songfile.cpp
+++ b/muse2/muse/songfile.cpp
@@ -56,49 +56,6 @@ MusECore::CloneList cloneList;
 namespace MusECore {
 
 
-/* DELETETHIS 42
-//---------------------------------------------------------
-//   updateCloneList
-//---------------------------------------------------------
-
-void updateCloneList(Part* oPart, Part* nPart)
-{
-  for(iClone i = MusEGlobal::cloneList.begin(); i != MusEGlobal::cloneList.end(); ++i) 
-  {
-    if(i->cp == oPart) 
-    {
-      i->cp = nPart;
-      break;
-    }
-  }
-}
-
-void updateCloneList(PartList* oParts, PartList* nParts)
-{
-  for(iPart ip = oParts->begin(); ip != oParts->end(); ++ip) 
-  {
-    for(iClone i = MusEGlobal::cloneList.begin(); i != MusEGlobal::cloneList.end(); ++i) 
-    {
-      if(i->cp == oPart) 
-      {
-        i->cp = nPart;
-        break;
-      }
-    }  
-  }
-}
-
-//---------------------------------------------------------
-//   clearClipboardAndCloneList
-//---------------------------------------------------------
-
-void clearClipboardAndCloneList()
-{
-  //QApplication::clipboard()->clear(QClipboard::Clipboard);
-  MusEGlobal::cloneList.clear();
-}
-*/
-
 //---------------------------------------------------------
 //   NKey::write
 //---------------------------------------------------------
@@ -167,10 +124,10 @@ void Scale::read(Xml& xml)
       }
 
 //---------------------------------------------------------
-//   readXmlPart
+//   Part::readFromXml
 //---------------------------------------------------------
 
-Part* readXmlPart(Xml& xml, Track* track, bool doClone, bool toTrack)
+Part* Part::readFromXml(Xml& xml, Track* track, bool doClone, bool toTrack)
       {
       int id = -1;
       Part* npart = 0;
@@ -197,7 +154,7 @@ Part* readXmlPart(Xml& xml, Track* track, bool doClone, bool toTrack)
                             {
                               if(i->id == id) // Is a matching part found in the clone list?
                               {
-                                // This makes a clone, chains the part, and increases ref counts.
+                                // Create a clone. It must still be added later in a operationgroup
                                 npart = track->newPart((Part*)i->cp, true);
                                 break;
                               }
@@ -242,7 +199,7 @@ Part* readXmlPart(Xml& xml, Track* track, bool doClone, bool toTrack)
                                 if(!doClone && !isclone)
                                   break;
                                   
-                                // This makes a clone, chains the part, and increases ref counts.
+                                // Create a clone. It must still be added later in a operationgroup
                                 npart = track->newPart((Part*)i->cp, true);
                                 break;
                               }
@@ -340,14 +297,6 @@ Part* readXmlPart(Xml& xml, Track* track, bool doClone, bool toTrack)
                                 e.move( -npart->tick() );
                                 int tick = e.tick();  
                                 
-                                // DELETETHIS 7
-                                // Do not discard events belonging to clone parts,
-                                //  at least not yet. A later clone might have a longer, 
-                                //  fully accommodating part length!
-                                //if ((tick < 0) || (tick >= (int) lenTick())) {
-                                //if ((tick < 0) || ( id == -1 && !clone && (tick >= (int)lenTick()) )) 
-                                // No way to tell at the moment whether there will be clones referencing this...
-                                // No choice but to accept all events past 0.
                                 if(tick < 0) 
                                 {
                                   printf("readClone: warning: event at tick:%d not in part:%s, discarded\n",
@@ -355,7 +304,7 @@ Part* readXmlPart(Xml& xml, Track* track, bool doClone, bool toTrack)
                                 }
                                 else 
                                 {
-                                  npart->events()->add(e);
+                                  npart->_events.add(e);
                                 }      
                               }
                               else // ...Otherwise a clone was created, so we don't need the events.
@@ -373,25 +322,6 @@ Part* readXmlPart(Xml& xml, Track* track, bool doClone, bool toTrack)
                         else if (tag == "cloneId")
                         {
                           id = xml.s2().toInt();
-                          //if(id != -1) DELETETHIS 19
-                          //{
-                          //  for(iClone i = MusEGlobal::cloneList.begin(); i != MusEGlobal::cloneList.end(); ++i) 
-                          //  {
-                              // Is a matching part found in the clone list?
-                          //    if(i->id == id) 
-                          //    {
-                                // If it's a regular paste (not paste clone), and the original part is
-                                //  not a clone, defer so that a new copy is created in TagStart above.
-                                //if(!doClone && i->cp->cevents()->arefCount() <= 1)
-                                //if(!doClone && !isclone)
-                                //  break;
-                                  
-                                // This makes a clone, chains the part, and increases ref counts.
-                          //      npart = track->newPart((Part*)i->cp, true);
-                          //      break;
-                          //    }
-                          //  }
-                          //}  
                         }      
                         else if (tag == "uuid")
                         {
@@ -399,55 +329,6 @@ Part* readXmlPart(Xml& xml, Track* track, bool doClone, bool toTrack)
                           if(!uuid_is_null(uuid))
                           {
                             uuidvalid = true;
-                            /* DELETETHIS 50
-                            for(iClone i = MusEGlobal::cloneList.begin(); i != MusEGlobal::cloneList.end(); ++i) 
-                            {
-                              // Is a matching part found in the clone list?
-                              if(uuid_compare(uuid, i->uuid) == 0) 
-                              {
-                                Track* cpt = i->cp->track();
-                                // If we want to paste to the given track...
-                                if(toTrack)
-                                {
-                                  // If the given track type is not the same as the part's 
-                                  //  original track type, we can't continue. Just return.
-                                  if(!track || cpt->type() != track->type())
-                                  {
-                                    xml.skip("part");
-                                    return 0;
-                                  }  
-                                }
-                                else
-                                // ...else we want to paste to the part's original track.
-                                {
-                                  // Make sure the track exists (has not been deleted).
-                                  if((cpt->isMidiTrack() && MusEGlobal::song->midis()->find(cpt) != MusEGlobal::song->midis()->end()) || 
-                                     (cpt->type() == Track::WAVE && MusEGlobal::song->waves()->find(cpt) != MusEGlobal::song->waves()->end()))
-                                    track = cpt;   
-                                  else
-                                  // Track was not found. Try pasting to the given track, as above...
-                                  {
-                                    if(!track || cpt->type() != track->type())
-                                    {
-                                      // No luck. Just return.
-                                      xml.skip("part");
-                                      return 0;
-                                    }  
-                                  }
-                                }
-                                
-                                // If it's a regular paste (not paste clone), and the original part is
-                                //  not a clone, defer so that a new copy is created in TagStart above.
-                                //if(!doClone && i->cp->cevents()->arefCount() <= 1)
-                                if(!doClone && !isclone)
-                                  break;
-                                  
-                                // This makes a clone, chains the part, and increases ref counts.
-                                npart = track->newPart((Part*)i->cp, true);
-                                break;
-                              }
-                            }
-                            */  
                           }
                         }      
                         else if(tag == "isclone")        
@@ -471,7 +352,6 @@ Part* readXmlPart(Xml& xml, Track* track, bool doClone, bool toTrack)
 
 void Part::write(int level, Xml& xml, bool isCopy, bool forceWavePaths) const
       {
-      const EventList* el = cevents();
       int id              = -1;
       uuid_t uuid; 
       uuid_clear(uuid);
@@ -482,7 +362,7 @@ void Part::write(int level, Xml& xml, bool isCopy, bool forceWavePaths) const
       {
         for(iClone i = MusEGlobal::cloneList.begin(); i != MusEGlobal::cloneList.end(); ++i) 
         {
-          if(i->cp->cevents() == el) 
+          if(i->cp->isCloneOf(this)) 
           {
             uuid_copy(uuid, i->uuid);
             dumpEvents = false;
@@ -498,11 +378,11 @@ void Part::write(int level, Xml& xml, bool isCopy, bool forceWavePaths) const
       }  
       else
       {
-        if (el->arefCount() > 1) 
+        if (this->hasClones()) 
         {
           for (iClone i = MusEGlobal::cloneList.begin(); i != MusEGlobal::cloneList.end(); ++i) 
           {
-            if (i->cp->cevents() == el) 
+            if (i->cp->isCloneOf(this)) 
             {
               id = i->id;
               dumpEvents = false;
@@ -531,7 +411,7 @@ void Part::write(int level, Xml& xml, bool isCopy, bool forceWavePaths) const
         else  
           xml.nput(level, "<part uuid=\"%s\"", sid);
         
-        if(el->arefCount() > 1)
+        if(hasClones())
           xml.nput(" isclone=\"1\"");
         xml.put(">");
         level++;  
@@ -552,292 +432,12 @@ void Part::write(int level, Xml& xml, bool isCopy, bool forceWavePaths) const
       if (_mute)
             xml.intTag(level, "mute", _mute);
       if (dumpEvents) {
-            for (ciEvent e = el->begin(); e != el->end(); ++e)
+            for (ciEvent e = events().begin(); e != events().end(); ++e)
                   e->second.write(level, xml, *this, forceWavePaths);
             }
       xml.etag(level, "part");
       }
 
-// DELETETHIS 280! whoa!
-/*
-//---------------------------------------------------------
-//   Part::read
-//---------------------------------------------------------
-
-void Part::read(Xml& xml, int, bool toTrack)    // int newPartOffset
-      {
-      int id = -1;
-      bool containsEvents = false;
-      uuid_t uuid; 
-      uuid_clear(uuid);
-      bool uuidvalid = false;
-      bool clone = false;
-
-      for (;;) {
-            Xml::Token token = xml.parse();
-            const QString& tag = xml.s1();
-            switch (token) {
-                  case Xml::Error:
-                  case Xml::End:
-                        return;
-                  case Xml::TagStart:
-                        if (tag == "name")
-                              _name = xml.parse1();
-                        else if (tag == "poslen") {
-                              PosLen::read(xml, "poslen");
-                              }
-                        else if (tag == "pos") {
-                              Pos pos;
-                              pos.read(xml, "pos");  // obsolete
-                              setTick(pos.tick());
-                              }
-                        else if (tag == "len") {
-                              Pos len;
-                              len.read(xml, "len");  // obsolete
-                              setLenTick(len.tick());
-                              }
-                        else if (tag == "selected")
-                              _selected = xml.parseInt();
-                        else if (tag == "color")
-                              _colorIndex = xml.parseInt();
-                        else if (tag == "mute")
-                              _mute = xml.parseInt();
-                        else if (tag == "event") {
-                              containsEvents = true;
-                              EventType type = Wave;
-                              if (_track->isMidiTrack())
-                                    type = Note;
-                              Event e(type);
-                              e.read(xml);
-                              // stored tickpos for event has absolute value. However internally
-                              // tickpos is relative to start of part, we substract tick().
-                              // TODO: better handling for wave event
-                              e.move(-tick());
-                              int tick = e.tick();  
-                              
-                              // Changed by T356. Do not discard events belonging to clone parts,
-                              //  at least not yet. A later clone might have a longer, 
-                              //  fully accommodating part length!
-                              //if ((tick < 0) || (tick >= (int) lenTick())) {
-                              if ((tick < 0) || ( id == -1 && !clone && (tick >= (int)lenTick()) )) 
-                              {
-                                    //printf("Part::read: warning: event not in part: %d - %d -%d, discarded\n",
-                                    printf("Part::read: warning: event at tick:%d not in part:%s, discarded\n",
-                                       tick, name().toLatin1().constData());
-                              }
-                              else {
-                                    _events->add(e);
-*/                                    
-                                    
-                                    
-                                    /*
-                                    // TODO: This should NOT be done here since the event list
-                                    //  might be deleted below. Since after reading a part it
-                                    //  likely (always?) that (msg)AddPart() or (msg)ChangePart()
-                                    //  will be called (must check if they're ever called BEFORE 
-                                    //  Part::read), then those routines will take care of it,
-                                    //  they are already coded to do so. 
-                                    // Note the redundancy of doing it here AND (msg)Add/ChangePart !
-                                    // Try to eliminate this section altogether by verifying that
-                                    //  (msg)Add/ChangePart (or one of the other routines which add port
-                                    //  controller values) is always called after Part::read...
-                                    if (e.type() == Controller) {
-                                          MidiTrack* mt = (MidiTrack*)_track;
-                                          int channel = mt->outChannel();
-                                          MidiPort* mp = &MusEGlobal::midiPorts[mt->outPort()];
-                                          // tick is relative to part, controller needs an absolute value hence
-                                          // part offset is added. If newPartOffset was given we use that instead of
-                                          // the recorded offset!
-                                          if (!newPartOffset)
-                                            newPartOffset=this->tick();
-
-                                          int ctl = e.dataA();
-                                          if(mt->type() == Track::DRUM)
-                                          {
-                                            // Is it a drum controller event, according to the track port's instrument?
-                                            MidiController* mc = mp->drumController(ctl);
-                                            if(mc)
-                                            {
-                                              int note = ctl & 0x7f;
-                                              ctl &= ~0xff;
-                                              channel = drumMap[note].channel;
-                                              mp = &MusEGlobal::midiPorts[drumMap[note].port];
-                                              ctl |= drumMap[note].anote;
-                                            }
-                                          }  
-                                          
-                                          // Removed by T356
-                                          // check if controller exists
-                                          //if (mp->hwCtrlState(channel, e.dataA()) == CTRL_VAL_UNKNOWN) {
-                                          //      mp->addManagedController(channel, e.dataA());
-                                          //      }
-                                          
-                                          // Changed by T356
-                                          // add controller value
-                                          //mp->setCtrl(channel, tick+newPartOffset, e.dataA(), e.dataB());
-                                          mp->setControllerVal(channel, tick+newPartOffset, ctl, e.dataB(), this);
-                                          }
-                                      */
-/*                                    
-                                    }
-                              }
-                        else
-                              xml.unknown("Part::read");
-                        break;
-                  case Xml::Attribut:
-                        if (tag == "cloneId")
-                              id = xml.s2().toInt();
-                        else if (tag == "uuid")
-                              {
-                                uuid_parse(xml.s2().toLatin1().constData(), uuid);
-                                if(!uuid_is_null(uuid))
-                                  uuidvalid = true;
-                              }  
-                        else if (tag == "isclone")
-                              clone = xml.s2().toInt();
-                        break;
-                  case Xml::TagEnd:
-                        if (tag == "part") 
-                        {
-*/                              
-                              /*
-                              if (id != -1) 
-                              {
-                                    
-                                    // clone part
-                                    if (containsEvents) {
-                                          // add to MusEGlobal::cloneList:
-                                          //ClonePart cp(_events, id);
-                                          ClonePart cp(this, id);
-                                          MusEGlobal::cloneList.push_back(cp);
-                                          }
-                                    else {
-                                          // replace event list with clone event
-                                          // list
-                                          for (iClone i = MusEGlobal::cloneList.begin();
-                                             i != MusEGlobal::cloneList.end(); ++i) {
-                                                if (i->id == id) {
-                                                      delete _events;
-                                                      //_events = (EventList*)(i->el);
-                                                      _events = (EventList*)(i->cp->cevents());
-                                                      _events->incRef(1);
-                                                      _events->incARef(1);
-                                                      //i->cp->chainClone(this);
-                                                      chainClone((Part*)i->cp, this);
-                                                      break;
-                                                      }
-                                                }
-                                          }
-                                */          
-                                          
-/*                          
-                          if(id != -1) 
-                          {
-                            // See if the part exists in the clone list. 
-                            // The clone list is also the copy/paste clone list.
-                            // Care must be taken to ensure the list is ALWAYS EMPTY 
-                            //  before loading or dropping parts INTO muse, because the
-                            //  current song parts are NOT the same as when the imported parts 
-                            //  were created, (even if they were created from the current session,
-                            //  we should NOT look them up). Always back up the list, clear it,
-                            //  read part(s), then restore the list so that paste works after.
-                            Part* cp = 0;
-                            for(iClone i = MusEGlobal::cloneList.begin(); i != MusEGlobal::cloneList.end(); ++i) 
-                            {  
-                              if(i->id == id) 
-                              {
-                                cp = (Part*)i->cp;
-                                break;
-                              }
-                            }
-                            // Was a matching part found in the clone list?
-                            if(cp)
-                            {
-                              // Make this part a clone of that part. Use its event list...
-                              delete _events;
-                              _events = (EventList*)(cp->cevents());
-                              _events->incRef(1);
-                              _events->incARef(1);
-                              chainClone(cp, this);
-                            }
-                            else                                
-                            {
-                              // No matching part to clone was found in the clone list. 
-                              // Does the part contain some events?
-                              //if(containsEvents) 
-                              {
-                                // Add the part to the clone list so that subsequent parts
-                                //  can look it up and clone from it...
-                                ClonePart ncp(this, id);
-                                MusEGlobal::cloneList.push_back(ncp);
-                              }
-                              // Otherwise this part has no matching part in the clone list
-                              //  and no events of its own. Nothing left to do, we now have 
-                              //  a blank part with the original offset, colour etc.
-                            }
-                          }
-                          else
-                          // If a uuid was found, do the same as above. Using uuids  
-                          //  allows foolproof rejection of copied parts not found 
-                          //  in the clone list, particularly when copying parts from 
-                          //  another instance of muse.
-                          if(uuidvalid) 
-                          {
-                            Part* cp = 0;
-                            for(iClone i = MusEGlobal::cloneList.begin(); i != MusEGlobal::cloneList.end(); ++i) 
-                            {  
-                              if(uuid_compare(uuid, i->uuid) == 0) 
-                              {
-                                cp = (Part*)i->cp;
-                                break;
-                              }
-                            }
-                            // If a matching part was found, and we want to paste to the original track...
-                            if(cp && !toTrack)
-                            {
-                              // Make sure the track exists (has not been deleted).
-                              if((cp->track()->isMidiTrack() && MusEGlobal::song->midis()->find(cp->track()) != MusEGlobal::song->midis()->end()) || 
-                                 (cp->track()->type() == Track::WAVE && MusEGlobal::song->waves()->find(cp->track()) != MusEGlobal::song->waves()->end()))
-                                setTrack(cp->track());
-                            }  
-                            // Was a matching part found in the clone list, and was it 
-                            //  originally a clone part?
-                            if(cp && clone)
-                            {
-                              // Make this part a clone of that part. Use its event list...
-                              delete _events;
-                              _events = (EventList*)(cp->cevents());
-                              _events->incRef(1);
-                              _events->incARef(1);
-                              // Chain the clone.
-                              // Use the slower function which makes sure it chains to a part
-                              //  within a valid (non-deleted) track.
-                              //chainClone(cp, this);
-                              chainClone(this);
-                            }
-                            else                                
-                            {
-                              // No matching part to clone was found in the clone list. 
-                              // Does the part contain some events?
-                              //if(containsEvents) 
-                              {
-                                // Add the part to the clone list so that subsequent parts
-                                //  can look it up and clone from it...
-                                ClonePart ncp(this);
-                                // New ClonePart creates its own uuid, but we need to replace it.
-                                uuid_copy(ncp.uuid, uuid);
-                                MusEGlobal::cloneList.push_back(ncp);
-                              }
-                            }
-                          }
-                          return;
-                        }
-                  default:
-                        break;
-                  }
-            }
-      }
-*/
 
 //---------------------------------------------------------
 //   writeFont
diff --git a/muse2/muse/steprec.cpp b/muse2/muse/steprec.cpp
index 723fe650..44da5a7e 100644
--- a/muse2/muse/steprec.cpp
+++ b/muse2/muse/steprec.cpp
@@ -55,7 +55,7 @@ void StepRec::timeout()
 	}
 }
 
-void StepRec::record(Part* part, int pitch, int len, int step, int velo, bool ctrl, bool shift, int incoming_pitch)
+void StepRec::record(const Part* part, int pitch, int len, int step, int velo, bool ctrl, bool shift, int incoming_pitch)
 {
 	unsigned tick = MusEGlobal::song->cpos();
 	unsigned lasttick=0;
@@ -76,12 +76,12 @@ void StepRec::record(Part* part, int pitch, int len, int step, int velo, bool ct
 		chord_timer->stop();
 
 		// extend len of last note?
-		EventList* events = part->events();
+		const EventList& events = part->events();
 		if (ctrl)
 		{
-			for (iEvent i = events->begin(); i != events->end(); ++i)
+			for (ciEvent i = events.begin(); i != events.end(); ++i)
 			{
-				Event ev = i->second;
+				const Event& ev = i->second;
 				if (ev.isNote() && ev.pitch() == pitch && ((ev.tick() + ev.lenTick() + part->tick()) == tick))
 				{
 					Event e = ev.clone();
@@ -106,13 +106,13 @@ void StepRec::record(Part* part, int pitch, int len, int step, int velo, bool ct
 			// if we would find a note after part->lenTick(), the above "if"
 			// avoids this. this has to be avoided because then part->hasHiddenEvents() is true
 			// which results in forbidding any action beyond its end
-			EventRange range = events->equal_range(tick - part->tick());
-			for (iEvent i = range.first; i != range.second; ++i)
+			EventRange range = events.equal_range(tick - part->tick());
+			for (ciEvent i = range.first; i != range.second; ++i)
 			{
-				Event ev = i->second;
+				const Event& ev = i->second;
 				if (ev.isNote() && ev.pitch() == pitch)
 				{
-					MusEGlobal::audio->msgDeleteEvent(ev, part, true, false, false);
+					MusEGlobal::song->applyOperation(UndoOp(UndoOp::DeleteEvent,ev, part, true,true));
 
 					if (!shift)
 					{
@@ -161,18 +161,18 @@ void StepRec::record(Part* part, int pitch, int len, int step, int velo, bool ct
 			// extend len of last note(s)
 			using std::set;
 			
-			set<Event*> extend_set;
-			EventList* events = part->events();
-			for (iEvent i = events->begin(); i != events->end(); ++i)
+			set<const Event*> extend_set;
+			const EventList& events = part->events();
+			for (ciEvent i = events.begin(); i != events.end(); ++i)
 			{
-				Event& ev = i->second;
+				const Event& ev = i->second;
 				if (ev.isNote() && note_held_down[ev.pitch()] && ((ev.tick() + ev.lenTick() + part->tick()) == tick))
 					extend_set.insert(&ev);
 			}
 			
-			for (set<Event*>::iterator it=extend_set.begin(); it!=extend_set.end(); it++)
+			for (set<const Event*>::iterator it=extend_set.begin(); it!=extend_set.end(); it++)
 			{
-				Event& ev=**it;
+				const Event& ev=**it;
 				Event e = ev.clone();
 				e.setLenTick(ev.lenTick() + len);
 				operations.push_back(UndoOp(UndoOp::ModifyEvent,e, ev, part, false, false));
diff --git a/muse2/muse/steprec.h b/muse2/muse/steprec.h
index a82cab20..f99fffc4 100644
--- a/muse2/muse/steprec.h
+++ b/muse2/muse/steprec.h
@@ -37,7 +37,7 @@ class StepRec : public QObject
 	public:
 		StepRec(bool* note_held_down_array);
 		
-		void record(Part* part,  int recorded_pitch, int len, int step, int velo=80, bool ctrl=false, bool shift=false, int incoming_pitch=1337);
+		void record(const Part* part,  int recorded_pitch, int len, int step, int velo=80, bool ctrl=false, bool shift=false, int incoming_pitch=1337);
 	
 	private slots:
 	  void timeout();
diff --git a/muse2/muse/structure.cpp b/muse2/muse/structure.cpp
index 65489cac..0c1d673d 100644
--- a/muse2/muse/structure.cpp
+++ b/muse2/muse/structure.cpp
@@ -5,6 +5,7 @@
 //
 //  (C) Copyright 1999-2004 Werner Schweer (ws@seh.de)
 //  (C) Copyright 2011  Robert Jonsson (rj@spamatica.se)
+//  (C) Copyright 2013  Florian Jung (flo93@sourceforge.net)
 //
 //  This program is free software; you can redistribute it and/or
 //  modify it under the terms of the GNU General Public License
@@ -161,19 +162,15 @@ void globalCut(bool onlySelectedTracks)
                   else if ((t < lpos) && ((t+l) > lpos) && ((t+l) <= rpos)) {
                       // remove part tail
                       int len = lpos - t;
-                      Part *nPart;
-                      if (track->isMidiTrack())
-                        nPart = new MidiPart(*(MidiPart*)part);
-                      else
-                        nPart = new WavePart(*(WavePart*)part);
-
-                      nPart->setLenTick(len);
-                      // cut Events in nPart
-                      EventList* el = nPart->events();
-                      for (iEvent ie = el->lower_bound(len); ie != el->end(); ++ie)
-                            operations.push_back(UndoOp(UndoOp::DeleteEvent,ie->second, nPart, false, false));
-
-                      operations.push_back(UndoOp(UndoOp::ModifyPart,part, nPart, true, true));
+                      
+                      if (part->nextClone()==part) // no clones
+                      {
+                            // cut Events
+                            const EventList& el = part->events();
+                            for (ciEvent ie = el.lower_bound(len); ie != el.end(); ++ie)
+                                    operations.push_back(UndoOp(UndoOp::DeleteEvent,ie->second, part, false, false));
+                      }
+                      operations.push_back(UndoOp(UndoOp::ModifyPartLength, part, part->lenTick(), len, true, true));
                   }
                   else if ((t < lpos) && ((t+l) > lpos) && ((t+l) > rpos)) {
                         //----------------------
@@ -182,16 +179,15 @@ void globalCut(bool onlySelectedTracks)
                         Part* p1;
                         Part* p2;
                         Part* p3;
-                        track->splitPart(part, lpos, p1, p2);
+                        part->splitPart(lpos, p1, p2);
                         delete p2;
-                        track->splitPart(part, rpos, p2, p3);
+                        part->splitPart(rpos, p2, p3);
                         delete p2;
                         p3->setTick(lpos);
-                        p1->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it so we must decrement it first :/
-                        p3->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it so we must decrement it first :/
 
-                        // Indicate no undo, and do port controller values and clone parts.
-                        operations.push_back(UndoOp(UndoOp::ModifyPart,part, p1, true, true));
+                        MusEGlobal::song->informAboutNewParts(part,p1,p3);
+                        operations.push_back(UndoOp(UndoOp::DeletePart,part));
+                        operations.push_back(UndoOp(UndoOp::AddPart,p1));
                         operations.push_back(UndoOp(UndoOp::AddPart,p3));
                         }
                   else if ((t >= lpos) && (t < rpos) && (t+l) > rpos) {
@@ -199,23 +195,18 @@ void globalCut(bool onlySelectedTracks)
                         
                         Part* p1;
                         Part* p2;
-                        track->splitPart(part, rpos, p1, p2);
+                        part->splitPart(rpos, p1, p2);
                         delete p1;
                         p2->setTick(lpos);
-                        p2->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it so we must decrement it first :/
-                        operations.push_back(UndoOp(UndoOp::ModifyPart,part, p2, true, true));
+                        
+                        MusEGlobal::song->informAboutNewParts(part,p2);
+                        operations.push_back(UndoOp(UndoOp::DeletePart,part));
+                        operations.push_back(UndoOp(UndoOp::AddPart,p2));
                         }
                   else if (t >= rpos) {
                         // move part to the left
-                        Part *nPart;
-                        if (track->isMidiTrack())
-                          nPart = new MidiPart(*(MidiPart*)part);
-                        else
-                          nPart = new WavePart(*(WavePart*)part);
                         int nt = part->tick();
-                        nPart->setTick(nt - (rpos -lpos));
-                        // Indicate no undo, and do port controller values but not clone parts.
-                        operations.push_back(UndoOp(UndoOp::ModifyPart,part, nPart, true, false));
+                        operations.push_back(UndoOp(UndoOp::ModifyPartTick,part,part->tick(), nt - (rpos -lpos) ));
                         }
                   }
             }
@@ -263,22 +254,16 @@ Undo movePartsTotheRight(unsigned int startTicks, int moveTicks, bool only_selec
                         // split part to insert new space
                         Part* p1;
                         Part* p2;
-                        track->splitPart(part, startTicks, p1, p2);
+                        part->splitPart(startTicks, p1, p2);
                         p2->setTick(startTicks+moveTicks);
-                        p2->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it so we must decrement it first :/
-                        p1->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it so we must decrement it first :/
 
-                        operations.push_back(UndoOp(UndoOp::ModifyPart, part, p1, true, true));
+                        MusEGlobal::song->informAboutNewParts(part,p1,p2);
+                        operations.push_back(UndoOp(UndoOp::DeletePart, part));
+                        operations.push_back(UndoOp(UndoOp::AddPart, p1));
                         operations.push_back(UndoOp(UndoOp::AddPart, p2));
                         }
                   else if (t >= startTicks) {
-                        Part *nPart;
-                        if (track->isMidiTrack())
-                          nPart = new MidiPart(*(MidiPart*)part);
-                        else
-                          nPart = new WavePart(*(WavePart*)part);
-                        nPart->setTick(t + moveTicks);
-                        operations.push_back(UndoOp(UndoOp::ModifyPart, part, nPart, true, false));
+                        operations.push_back(UndoOp(UndoOp::ModifyPartTick, part, part->tick(), t + moveTicks));
                         }
                   }
             }
@@ -318,24 +303,17 @@ Undo partSplitter(unsigned int pos, bool onlySelectedTracks)
               if (pos > p1 && pos < (p1+l0)) {
                     Part* p1;
                     Part* p2;
-                    track->splitPart(part, pos, p1, p2);
+                    part->splitPart(pos, p1, p2);
 
-                    p1->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it
-                    p2->events()->incARef(-1); // so we must decrement it first :/
-
-                    //MusEGlobal::song->informAboutNewParts(part, p1); // is unneccessary because of ModifyPart
+                    MusEGlobal::song->informAboutNewParts(part, p1);
                     MusEGlobal::song->informAboutNewParts(part, p2);
-                    operations.push_back(UndoOp(UndoOp::ModifyPart,part, p1, true, false));
+                    operations.push_back(UndoOp(UndoOp::DeletePart,part));
+                    operations.push_back(UndoOp(UndoOp::AddPart,p1));
                     operations.push_back(UndoOp(UndoOp::AddPart,p2));
-                    if (MusEGlobal::debugMsg)
-                    {
-                          printf("in partSplitter: part1 %d\n",p1->events()->refCount());
-                          printf("in partSplitter: part2 %d\n",p2->events()->refCount());
-                          }
                     break;
-                    }
               }
         }
+    }
     return operations;
 }
 
diff --git a/muse2/muse/synth.cpp b/muse2/muse/synth.cpp
index d8d09048..32568e31 100644
--- a/muse2/muse/synth.cpp
+++ b/muse2/muse/synth.cpp
@@ -696,11 +696,7 @@ SynthI* Song::createSynthI(const QString& sclass, const QString& label, Synth::T
       
       int idx = insertAt ? _tracks.index(insertAt) : -1;
       
-      insertTrack1(si, idx);
-      
-      msgInsertTrack(si, idx, true);       // add to instance list
-      
-      insertTrack3(si, idx);
+      MusEGlobal::song->applyOperation(UndoOp(UndoOp::AddTrack, idx, si));
 
       OutputList* ol = MusEGlobal::song->outputs();
       // add default route to master (first audio output)
diff --git a/muse2/muse/track.cpp b/muse2/muse/track.cpp
index cc1e56ac..8d30fccb 100644
--- a/muse2/muse/track.cpp
+++ b/muse2/muse/track.cpp
@@ -66,9 +66,9 @@ void addPortCtrlEvents(MidiTrack* t)
   for(ciPart ip = pl->begin(); ip != pl->end(); ++ip)
   {
     Part* part = ip->second;
-    const EventList* el = part->cevents();
+    const EventList& el = part->events();
     unsigned len = part->lenTick();
-    for(ciEvent ie = el->begin(); ie != el->end(); ++ie)
+    for(ciEvent ie = el.begin(); ie != el.end(); ++ie)
     {
       const Event& ev = ie->second;
       // Added by T356. Do not add events which are past the end of the part.
@@ -116,8 +116,8 @@ void removePortCtrlEvents(MidiTrack* t)
   for(ciPart ip = pl->begin(); ip != pl->end(); ++ip)
   {
     Part* part = ip->second;
-    const EventList* el = part->cevents();
-    for(ciEvent ie = el->begin(); ie != el->end(); ++ie)
+    const EventList& el = part->events();
+    for(ciEvent ie = el.begin(); ie != el.end(); ++ie)
     {
       const Event& ev = ie->second;
                     
@@ -468,8 +468,6 @@ MidiTrack::MidiTrack()
    : Track(MIDI)
       {
       init();
-      _events = new EventList;
-      _mpevents = new MPEventList;
       clefType=trebleClef;
       
       _drummap=new DrumMap[128];
@@ -481,9 +479,6 @@ MidiTrack::MidiTrack()
 MidiTrack::MidiTrack(const MidiTrack& mt, int flags)
   : Track(mt, flags)
 {
-      _events   = new EventList;
-      _mpevents = new MPEventList;
-
       _drummap=new DrumMap[128];
       _drummap_hidden=new bool[128];
       
@@ -592,27 +587,11 @@ void MidiTrack::internal_assign(const Track& t, int flags)
         const PartList* pl = t.cparts();
         for (ciPart ip = pl->begin(); ip != pl->end(); ++ip) {
               Part* spart = ip->second;
-              bool clone = spart->events()->arefCount() > 1;
-              // This increments aref count if cloned, and chains clones.
-              // It also gives the new part a new serial number.
-              Part* dpart = newPart(spart, clone);
-              if(!clone) {
-                    // Copy Events
-                    MusECore::EventList* se = spart->events();
-                    MusECore::EventList* de = dpart->events();
-                    for (MusECore::iEvent i = se->begin(); i != se->end(); ++i) {
-                          MusECore::Event oldEvent = i->second;
-                          MusECore::Event ev = oldEvent.clone();
-                          de->add(ev);
-                          }
-                    }
-
-              // TODO: Should we include the parts in the undo?      
-              //      dpart->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it
-              //                                    // so we must decrement it first :/
-              //      // These will not increment ref count, and will not chain clones...
-              //      // DELETETHIS: is the above comment still correct (by flo93)? i doubt it!
-              //      operations.push_back(MusECore::UndoOp(MusECore::UndoOp::AddPart,dpart));
+              Part* dpart;
+              if (spart->hasClones())
+                  dpart = spart->createNewClone();
+              else
+                  dpart = spart->duplicate();
 
               parts()->add(dpart);
               }
@@ -628,8 +607,6 @@ void MidiTrack::assign(const Track& t, int flags)
 
 MidiTrack::~MidiTrack()
       {
-      delete _events;
-      delete _mpevents;
       delete [] _drummap;
       delete [] _drummap_hidden;
       
@@ -803,90 +780,6 @@ void MidiTrack::setInPortAndChannelMask(unsigned int portmask, int chanmask)
   }  
 }
 
-/* DELETETHIS 84
-//---------------------------------------------------------
-//   addPortCtrlEvents
-//---------------------------------------------------------
-
-void MidiTrack::addPortCtrlEvents()
-{
-  const PartList* pl = cparts();
-  for(ciPart ip = pl->begin(); ip != pl->end(); ++ip)
-  {
-    Part* part = ip->second;
-    const EventList* el = part->cevents();
-    for(ciEvent ie = el->begin(); ie != el->end(); ++ie)
-    {
-      const Event& ev = ie->second;
-      if(ev.type() == Controller)
-      {
-        int tick  = ev.tick() + part->tick();
-        int cntrl = ev.dataA();
-        int val   = ev.dataB();
-        int ch = _outChannel;
-        
-        MidiPort* mp = &MusEGlobal::midiPorts[_outPort];
-        // Is it a drum controller event, according to the track port's instrument?
-        if(type() == DRUM)
-        {
-          MidiController* mc = mp->drumController(cntrl);
-          if(mc)
-          {
-            int note = cntrl & 0x7f;
-            cntrl &= ~0xff;
-            ch = MusEGlobal::drumMap[note].channel;
-            mp = &MusEGlobal::midiPorts[MusEGlobal::drumMap[note].port];
-            cntrl |= MusEGlobal::drumMap[note].anote;
-          }
-        }
-        
-        mp->setControllerVal(ch, tick, cntrl, val, part);
-      }
-    }
-  }
-}
-
-//---------------------------------------------------------
-//   removePortCtrlEvents
-//---------------------------------------------------------
-
-void MidiTrack::removePortCtrlEvents()
-{
-  const PartList* pl = cparts();
-  for(ciPart ip = pl->begin(); ip != pl->end(); ++ip)
-  {
-    Part* part = ip->second;
-    const EventList* el = part->cevents();
-    for(ciEvent ie = el->begin(); ie != el->end(); ++ie)
-    {
-      const Event& ev = ie->second;
-      if(ev.type() == Controller)
-      {
-        int tick  = ev.tick() + part->tick();
-        int cntrl = ev.dataA();
-        int ch = _outChannel;
-        
-        MidiPort* mp = &MusEGlobal::midiPorts[_outPort];
-        // Is it a drum controller event, according to the track port's instrument?
-        if(type() == DRUM)
-        {
-          MidiController* mc = mp->drumController(cntrl);
-          if(mc)
-          {
-            int note = cntrl & 0x7f;
-            cntrl &= ~0xff;
-            ch = MusEGlobal::drumMap[note].channel;
-            mp = &MusEGlobal::midiPorts[MusEGlobal::drumMap[note].port];
-            cntrl |= MusEGlobal::drumMap[note].anote;
-          }
-        }
-        
-        mp->deleteController(ch, tick, cntrl, part);
-      }
-    }
-  }
-}
-*/
 
 //---------------------------------------------------------
 //   newPart
@@ -894,7 +787,16 @@ void MidiTrack::removePortCtrlEvents()
 
 Part* MidiTrack::newPart(Part*p, bool clone)
       {
-      MidiPart* part = clone ? new MidiPart(this, p->events()) : new MidiPart(this);
+      MidiPart* part;
+      if (clone)
+      {
+            part = (MidiPart*)p->createNewClone();
+            part->setTrack(this);
+      }
+      else
+            part= new MidiPart(this);
+      
+      
       if (p) {
             part->setName(p->name());
             part->setColorIndex(p->colorIndex());
@@ -903,10 +805,6 @@ Part* MidiTrack::newPart(Part*p, bool clone)
             part->setMute(p->mute());
             }
       
-      if(clone)
-        //p->chainClone(part);
-        chainClone(p, part);
-      
       return part;
       }
 
@@ -1004,7 +902,7 @@ void MidiTrack::read(Xml& xml)
             switch (token) {
                   case Xml::Error:
                   case Xml::End:
-                        return;
+                        goto out_of_MidiTrackRead_forloop;
                   case Xml::TagStart:
                         if (tag == "transposition")
                               transposition = xml.parseInt();
@@ -1017,10 +915,7 @@ void MidiTrack::read(Xml& xml)
                         else if (tag == "compression")
                               compression = xml.parseInt();
                         else if (tag == "part") {
-                              //Part* p = newPart();
-                              //p->read(xml);
-                              Part* p = 0;
-                              p = readXmlPart(xml, this);
+                              Part* p = Part::readFromXml(xml, this);
                               if(p)
                                 parts()->add(p);
                               }
@@ -1094,12 +989,15 @@ void MidiTrack::read(Xml& xml)
                         if (tag == "miditrack" || tag == "drumtrack" || tag == "newdrumtrack") 
                         {
                           setInPortAndChannelMask(portmask, chanmask); // Support old files.
-                          return;
+                          goto out_of_MidiTrackRead_forloop;
                         }
                   default:
                         break;
                   }
             }
+      
+out_of_MidiTrackRead_forloop:
+      chainTrackParts(this);
       }
 
 void MidiTrack::readOurDrumSettings(Xml& xml)
@@ -1335,7 +1233,7 @@ int MidiTrack::getFirstControllerValue(int ctrl, int def)
   {
     Part* part=pit->second;
     if (part->tick() > tick) break; // ignore this and the rest. we won't find anything new.
-    for (iEvent eit=part->events()->begin(); eit!=part->events()->end(); eit++)
+    for (ciEvent eit=part->events().begin(); eit!=part->events().end(); eit++)
     {
       if (eit->first+part->tick() >= tick) break;
       if (eit->first > part->lenTick()) break; // ignore events past the end of the part
@@ -1359,7 +1257,7 @@ int MidiTrack::getControllerChangeAtTick(unsigned tick, int ctrl, int def)
     Part* part=pit->second;
     if (part->tick() > tick) break; // ignore this and the rest. we'd find nothing any more
     if (part->endTick() < tick) continue; // ignore only this.
-    for (iEvent eit=part->events()->begin(); eit!=part->events()->end(); eit++)
+    for (ciEvent eit=part->events().begin(); eit!=part->events().end(); eit++)
     {
       if (eit->first+part->tick() > tick) break; // we won't find anything in this part from now on.
       if (eit->first > part->lenTick()) break; // ignore events past the end of the part
@@ -1385,7 +1283,7 @@ unsigned MidiTrack::getControllerValueLifetime(unsigned tick, int ctrl)
     Part* part=pit->second;
     if (part->tick() > result) break; // ignore this and the rest. we won't find anything new.
     if (part->endTick() < tick) continue; // ignore only this part, we won't find anything there.
-    for (iEvent eit=part->events()->begin(); eit!=part->events()->end(); eit++)
+    for (ciEvent eit=part->events().begin(); eit!=part->events().end(); eit++)
     {
       if (eit->first+part->tick() >= result) break;
       if (eit->first > part->lenTick()) break; // ignore events past the end of the part
diff --git a/muse2/muse/track.h b/muse2/muse/track.h
index 664364ba..f3551ce0 100644
--- a/muse2/muse/track.h
+++ b/muse2/muse/track.h
@@ -32,6 +32,7 @@
 
 #include "wave.h" // for SndFileR
 #include "part.h"
+#include "mpevent.h"
 #include "key.h"
 #include "node.h"
 #include "route.h"
@@ -41,7 +42,6 @@
 #include "controlfifo.h"
 
 namespace MusECore {
-class MPEventList;
 class Pipeline;
 class PluginI;
 class SynthI;
@@ -158,7 +158,6 @@ class Track {
 
       virtual Part* newPart(Part*p=0, bool clone = false) = 0;
       void dump() const;
-      virtual void splitPart(Part*, int, Part*&, Part*&);
 
       virtual void setMute(bool val);
       virtual void setOff(bool val);
@@ -212,8 +211,11 @@ class MidiTrack : public Track {
       int _outChannel;
       bool _recEcho;              // For midi (and audio). Whether to echo incoming record events to output device.
 
-      EventList* _events;     // tmp Events during midi import
-      MPEventList* _mpevents; // tmp Events druring recording
+   public:
+      EventList events;     // tmp Events during midi import
+      MPEventList mpevents; // tmp Events druring recording
+
+   private:
       static bool _isVisible;
       clefTypes clefType;
 
@@ -255,9 +257,6 @@ class MidiTrack : public Track {
       virtual bool setRecordFlag1(bool f) { _recordFlag = f; return true;}
       virtual void setRecordFlag2(bool) {}
 
-      EventList* events() const          { return _events; }
-      MPEventList* mpevents() const      { return _mpevents; }
-
       virtual void read(Xml&);
       virtual void write(int, Xml&) const;
 
diff --git a/muse2/muse/undo.cpp b/muse2/muse/undo.cpp
index fc6fc1d8..103b47ac 100644
--- a/muse2/muse/undo.cpp
+++ b/muse2/muse/undo.cpp
@@ -21,6 +21,8 @@
 //
 //=========================================================
 
+#include "assert.h"
+
 //#include "sig.h"
 #include "al/sig.h"  
 #include "keyevent.h"
@@ -50,8 +52,9 @@ const char* UndoOp::typeName()
       {
       static const char* name[] = {
             "AddTrack", "DeleteTrack", 
-            "AddPart",  "DeletePart",  "ModifyPart",
-            "AddEvent", "DeleteEvent", "ModifyEvent",
+            "AddPart",  "DeletePart",  "ModifyPartTick", "ModifyPartLength", "ModifyPartLengthFrames", "ModifyPartName", "SelectPart",
+            "MovePartToTrack",
+            "AddEvent", "DeleteEvent", "ModifyEvent", "SelectEvent",
             "AddTempo", "DeleteTempo",
             "AddSig", "DeleteSig",
             "AddKey", "DeleteKey",
@@ -77,7 +80,11 @@ void UndoOp::dump()
                   break;
             case AddPart:
             case DeletePart:
-            case ModifyPart:
+            case ModifyPartTick:
+            case ModifyPartLength:
+            case ModifyPartLengthFrames:
+            case ModifyPartName:
+            case MovePartToTrack:
                   break;
             case AddEvent:
             case DeleteEvent:
@@ -132,15 +139,11 @@ void UndoList::clearDelete()
           {
             case UndoOp::DeleteTrack:
                   if(i->track)
-                    delete i->track;
+                    delete const_cast<Track*>(i->track);
                   break;
                   
             case UndoOp::DeletePart:
-                  delete i->oPart;
-                  break;
-
-            case UndoOp::ModifyPart:
-                  delete i->oPart;
+                  delete const_cast<Part*>(i->part);
                   break;
 
             case UndoOp::ModifyMarker:
@@ -176,12 +179,9 @@ void UndoList::clearDelete()
                   break;
                   
             case UndoOp::AddPart:
-                  delete i->oPart;
+                  delete i->part;
                   break;
 
-            case UndoOp::ModifyPart:
-                  delete i->nPart;
-                  break;
             case UndoOp::ModifyMarker:
                   if (i->realMarker)
                     delete i->realMarker;
@@ -213,9 +213,9 @@ void UndoList::clearDelete()
 void Song::startUndo()
       {
       redoList->clearDelete(); // redo must be invalidated when a new undo is started
-			MusEGlobal::redoAction->setEnabled(false);
+      MusEGlobal::redoAction->setEnabled(false);
       setUndoRedoText();
-			
+      
       undoList->push_back(Undo());
       updateFlags = 0;
       undoMode = true;
@@ -227,6 +227,15 @@ void Song::startUndo()
 
 void Song::endUndo(SongChangedFlags_t flags)
       {
+      riUndo prev_undo = undoList->rbegin();
+      prev_undo++;
+      if (prev_undo!=undoList->rend())
+      {
+            // try to merge the current Undo with the last one
+            if (prev_undo->merge_combo(undoList->back()))
+                  undoList->pop_back();
+      }
+      
       updateFlags |= flags;
       endMsgCmd();
       undoMode = false;
@@ -276,12 +285,49 @@ void Song::setUndoRedoText()
 }
 
 
-void cleanOperationGroup(Undo& group)
+bool Undo::merge_combo(const Undo& other)
 {
-	using std::set;
+	if (this->combobreaker || other.combobreaker)
+		return false;
+	
+	bool has_select_event=false;
+	bool has_select_part=false;
+	bool has_other=false;
+	
+	for (ciUndoOp op=this->begin(); op!=this->end(); op++)
+		switch(op->type)
+		{
+			case UndoOp::DoNothing: break;
+			case UndoOp::SelectEvent: has_select_event=true; break;
+			case UndoOp::SelectPart: has_select_part=true; break;
+			default: has_other=true; break;
+		}
+	
+	for (ciUndoOp op=other.begin(); op!=other.end(); op++)
+		switch(op->type)
+		{
+			case UndoOp::DoNothing: break;
+			case UndoOp::SelectEvent: has_select_event=true; break;
+			case UndoOp::SelectPart: has_select_part=true; break;
+			default: has_other=true; break;
+		}
+	
+	bool mergeable = (has_select_event && !has_select_part && !has_other) ||
+	                 (has_select_part && !has_select_event && !has_other);
+	
+	if (mergeable)
+		this->insert(this->end(), other.begin(), other.end());
+	
+	return mergeable;
+}
+
+void prepareOperationGroup(Undo& group)
+{
+	QSet<const Track*> deleted_tracks;
+	QSet<const Part*> deleted_parts;
+
+	int songlen = MusEGlobal::song->len();
 	
-	set<Track*> processed_tracks;
-	set<Part*> processed_parts;
 
 	for (iUndoOp op=group.begin(); op!=group.end();)
 	{
@@ -290,46 +336,108 @@ void cleanOperationGroup(Undo& group)
 		
 		if (op->type==UndoOp::DeleteTrack)
 		{
-			if (processed_tracks.find(op->track)!=processed_tracks.end())
+			if (deleted_tracks.contains(op->track))
+			{
 				group.erase(op);
+			}
 			else
-				processed_tracks.insert(op->track);
+			{
+				const PartList* pl = op->track->cparts();
+				for (ciPart part = pl->begin(); part != pl->end(); part++)
+					if (!deleted_parts.contains(part->second))
+					{
+						// they will be inserted between op and op_
+						// because we set op=op_ below, the inserted
+						// elements will be skipped.
+						group.insert(op, UndoOp(UndoOp::DeletePart, part->second));
+						deleted_parts.insert(part->second);
+					}
+					
+				deleted_tracks.insert(op->track);
+			}
 		}
-		else if ((op->type==UndoOp::ModifyPart) || (op->type==UndoOp::DeletePart))
+		else if (op->type==UndoOp::DeletePart)
 		{
-			if (processed_parts.find(op->oPart)!=processed_parts.end())
+			if (deleted_parts.contains(op->part))
 				group.erase(op);
 			else
-				processed_parts.insert(op->oPart);
+				deleted_parts.insert(op->part);
+		}
+		else if (op->type==UndoOp::AddPart || op->type==UndoOp::ModifyPartLength ||
+		         op->type==UndoOp::ModifyPartTick)
+		{
+			if (op->type==UndoOp::AddPart)
+			{
+				if (songlen < op->part->endTick())
+					songlen = op->part->endTick();
+			}
+			else if (op->type==UndoOp::ModifyPartTick)
+			{
+				if (songlen < op->new_partlen_or_tick+op->part->lenTick())
+					songlen = op->new_partlen_or_tick+op->part->lenTick();
+			}
+			else if (op->type==UndoOp::ModifyPartLength)
+			{
+				if (songlen < op->part->tick()+op->new_partlen_or_tick)
+					songlen=op->part->tick()+op->new_partlen_or_tick;
+			}
 		}
 		
 		op=op_;
 	}
+	
+	if (songlen >= MusEGlobal::song->len())
+		group.push_back(UndoOp(UndoOp::ModifySongLen, songlen, MusEGlobal::song->len()));
+	
+	// replicate Event modifications to keep clones up to date.
+	// do not replicate SelectEvent because... umm, it just doesn't feel right.
+	for (iUndoOp op=group.begin(); op!=group.end(); op++)
+	{
+		if (op->type==UndoOp::AddEvent || op->type==UndoOp::DeleteEvent || op->type==UndoOp::ModifyEvent)
+		{
+			for (const Part* it = op->part->nextClone(); it!=op->part; it=it->nextClone())
+			{
+				UndoOp newop;
+				if (op->type==UndoOp::AddEvent) // we need to clone the event
+					newop = UndoOp(UndoOp::AddEvent, op->nEvent.clone(), it, op->doCtrls, op->doClones);
+				else if (op->type==UndoOp::DeleteEvent)
+					newop = UndoOp(UndoOp::DeleteEvent, it->events().findSimilar(op->nEvent)->second, it, op->doCtrls, op->doClones);
+				else if (op->type==UndoOp::ModifyEvent)
+					newop = UndoOp(UndoOp::ModifyEvent, op->nEvent.clone(), it->events().findSimilar(op->oEvent)->second, it, op->doCtrls, op->doClones);
+				
+				group.insert(op, newop);
+			}
+		}
+	}
 }
 
+bool Song::applyOperation(const UndoOp& op, bool doUndo)
+{
+	Undo operations;
+	operations.push_back(op);
+	return applyOperationGroup(operations, doUndo);
+}
 
 bool Song::applyOperationGroup(Undo& group, bool doUndo)
 {
       if (!group.empty())
       {
-            cleanOperationGroup(group);
-            //this is a HACK! but it works :)    (added by flo93)
-            redoList->push_back(group);
-            redo();
+            prepareOperationGroup(group);
             
-            if (!doUndo)
-            {
-                  undoList->pop_back();
-                  MusEGlobal::undoAction->setEnabled(!undoList->empty());
-                  setUndoRedoText();
-            }
-            else
-            {
-                  redoList->clearDelete(); // redo must be invalidated when a new undo is started
-                  MusEGlobal::redoAction->setEnabled(false);
-                  setUndoRedoText();
-            }
+            if (doUndo)
+                 startUndo();
+
+            MusEGlobal::audio->msgExecuteOperationGroup(group);
             
+            // append all elements from "group" to the end of undoList->back().
+            Undo& curUndo = undoList->back();
+            curUndo.insert(curUndo.end(), group.begin(), group.end());
+            if (group.combobreaker)
+               curUndo.combobreaker=true;
+            
+            if (doUndo)
+                 endUndo(0);
+
             return doUndo;
       }
       else
@@ -339,22 +447,24 @@ bool Song::applyOperationGroup(Undo& group, bool doUndo)
 
 
 //---------------------------------------------------------
-//   doUndo2
+//   revertOperationGroup2
 //    real time part
 //---------------------------------------------------------
 
-void Song::doUndo2()
+void Song::revertOperationGroup2(Undo& operations)
       {
-      Undo& u = undoList->back();
-      for (riUndoOp i = u.rbegin(); i != u.rend(); ++i) {
+      for (riUndoOp i = operations.rbegin(); i != operations.rend(); ++i) {
+            Track* editable_track = const_cast<Track*>(i->track);
+// uncomment if needed            Track* editable_property_track = const_cast<Track*>(i->_propertyTrack);
+            Part* editable_part = const_cast<Part*>(i->part);
             switch(i->type) {
                   case UndoOp::AddTrack:
-                        removeTrack2(i->track);
+                        removeTrack2(editable_track);
                         updateFlags |= SC_TRACK_REMOVED;
                         break;
-                  case UndoOp::DeleteTrack:
-                        insertTrack2(i->track, i->trackno);
-                        chainTrackParts(i->track, true);
+                  case UndoOp::DeleteTrack: // FINDMICHJETZT FIXME TODO: DeletePart on all parts, only empty tracks may be deleted! this removes the necessarity of un...
+                        insertTrack2(editable_track, i->trackno);
+                        chainTrackParts(editable_track);
                         
                         updateFlags |= SC_TRACK_INSERTED;
                         break;
@@ -369,49 +479,55 @@ void Song::doUndo2()
                         }
                         break;
                   case UndoOp::AddPart:
-                        {
-                        Part* part = i->oPart;
-                        removePart(part);
+                        removePart(editable_part);
                         updateFlags |= SC_PART_REMOVED;
-                        i->oPart->events()->incARef(-1);
-                        unchainClone(i->oPart);
-                        }
+                        editable_part->unchainClone();
                         break;
                   case UndoOp::DeletePart:
-                        addPart(i->oPart);
+                        addPart(editable_part);
                         updateFlags |= SC_PART_INSERTED;
-                        i->oPart->events()->incARef(1);
-                        chainClone(i->oPart);
+                        editable_part->rechainClone();
                         break;
-                  case UndoOp::ModifyPart:
-                        if(i->doCtrls)
-                          removePortCtrlEvents(i->nPart, i->doClones);
-                        changePart(i->nPart, i->oPart);
-                        i->nPart->events()->incARef(-1);
-                        i->oPart->events()->incARef(1);
-                        replaceClone(i->nPart, i->oPart);
-                        if(i->doCtrls)
-                          addPortCtrlEvents(i->oPart, i->doClones);
+                  case UndoOp::MovePartToTrack:
+                        removePart(editable_part); // remove it from the track it currently lives on. (does not touch the clone chain)
+                        editable_part->setTrack(const_cast<Track*>(i->oldTrack));
+                        addPart(editable_part); // add it to the track we just set.
+                        updateFlags |= SC_PART_INSERTED | SC_PART_REMOVED;
+                        break;
+                  case UndoOp::ModifyPartName:
+                        editable_part->setName(i->_oldName);
+                        updateFlags |= SC_PART_MODIFIED;
+                        break;
+                  case UndoOp::ModifyPartTick: // TODO FIXME (?) do port ctrls/clones?
+                        editable_part->setTick(i->old_partlen_or_tick);
+                        updateFlags |= SC_PART_MODIFIED;
+                        break;
+                  case UndoOp::ModifyPartLength: // TODO FIXME (?) do port ctrls/clones?
+                        editable_part->setLenTick(i->old_partlen_or_tick);
+                        updateFlags |= SC_PART_MODIFIED;
+                        break;
+                  case UndoOp::ModifyPartLengthFrames: // TODO FIXME  FINDMICH frames deprecated!   do port ctrls/clones?
+                        editable_part->setLenFrame(i->old_partlen_or_tick);
                         updateFlags |= SC_PART_MODIFIED;
                         break;
                   case UndoOp::AddEvent:
                         if(i->doCtrls)
-                          removePortCtrlEvents(i->nEvent, i->part, i->doClones);
-                        deleteEvent(i->nEvent, i->part);
+                          removePortCtrlEvents(i->nEvent, editable_part, i->doClones);
+                        deleteEvent(i->nEvent, editable_part);
                         updateFlags |= SC_EVENT_REMOVED;
                         break;
                   case UndoOp::DeleteEvent:
-                        addEvent(i->nEvent, i->part);
+                        addEvent(i->nEvent, editable_part);
                         if(i->doCtrls)
-                          addPortCtrlEvents(i->nEvent, i->part, i->doClones);
+                          addPortCtrlEvents(i->nEvent, editable_part, i->doClones);
                         updateFlags |= SC_EVENT_INSERTED;
                         break;
                   case UndoOp::ModifyEvent:
                         if(i->doCtrls)
-                          removePortCtrlEvents(i->oEvent, i->part, i->doClones);
-                        changeEvent(i->oEvent, i->nEvent, i->part);
+                          removePortCtrlEvents(i->nEvent, editable_part, i->doClones);
+                        changeEvent(i->nEvent, i->oEvent, editable_part);
                         if(i->doCtrls)
-                          addPortCtrlEvents(i->nEvent, i->part, i->doClones);
+                          addPortCtrlEvents(i->oEvent, editable_part, i->doClones);
                         updateFlags |= SC_EVENT_MODIFIED;
                         break;
                   case UndoOp::AddTempo:
@@ -455,22 +571,24 @@ void Song::doUndo2()
       }
 
 //---------------------------------------------------------
-//   Song::doRedo2
+//   Song::executeOperationGroup2
 //---------------------------------------------------------
 
-void Song::doRedo2()
+void Song::executeOperationGroup2(Undo& operations)
       {
-      Undo& u = redoList->back();
-      for (iUndoOp i = u.begin(); i != u.end(); ++i) {
+      for (iUndoOp i = operations.begin(); i != operations.end(); ++i) {
+            Track* editable_track = const_cast<Track*>(i->track);
+// uncomment if needed            Track* editable_property_track = const_cast<Track*>(i->_propertyTrack);
+            Part* editable_part = const_cast<Part*>(i->part);
             switch(i->type) {
                   case UndoOp::AddTrack:
-                        insertTrack2(i->track, i->trackno);
-                        chainTrackParts(i->track, true);
+                        insertTrack2(editable_track, i->trackno);
+                        chainTrackParts(editable_track);
                         
                         updateFlags |= SC_TRACK_INSERTED;
                         break;
                   case UndoOp::DeleteTrack:
-                        removeTrack2(i->track);
+                        removeTrack2(editable_track);
                         updateFlags |= SC_TRACK_REMOVED;
                         break;
                         
@@ -484,46 +602,55 @@ void Song::doRedo2()
                         }
                         break;
                   case UndoOp::AddPart:
-                        addPart(i->oPart);
+                        addPart(editable_part);
                         updateFlags |= SC_PART_INSERTED;
-                        i->oPart->events()->incARef(1);
-                        chainClone(i->oPart);
+                        editable_part->rechainClone();
                         break;
                   case UndoOp::DeletePart:
-                        removePart(i->oPart);
+                        removePart(editable_part);
                         updateFlags |= SC_PART_REMOVED;
-                        i->oPart->events()->incARef(-1);
-                        unchainClone(i->oPart);
+                        editable_part->unchainClone();
                         break;
-                  case UndoOp::ModifyPart:
-                        if(i->doCtrls)
-                          removePortCtrlEvents(i->oPart, i->doClones);
-                        changePart(i->oPart, i->nPart);
-                        i->nPart->events()->incARef(1);
-                        i->oPart->events()->incARef(-1);
-                        replaceClone(i->oPart, i->nPart);
-                        if(i->doCtrls)
-                          addPortCtrlEvents(i->nPart, i->doClones);
+                  case UndoOp::MovePartToTrack:
+                        removePart(editable_part); // remove it from the track it currently lives on. (does not touch the clone chain)
+                        editable_part->setTrack(editable_track);
+                        addPart(editable_part); // add it to the track we just set.
+                        updateFlags |= SC_PART_INSERTED | SC_PART_REMOVED;
+                        break;
+                  case UndoOp::ModifyPartName:
+                        editable_part->setName(i->_newName);
+                        updateFlags |= SC_PART_MODIFIED;
+                        break;
+                  case UndoOp::ModifyPartTick: // TODO FIXME (?) do port ctrls/clones?
+                        editable_part->setTick(i->new_partlen_or_tick);
+                        updateFlags |= SC_PART_MODIFIED;
+                        break;
+                  case UndoOp::ModifyPartLength: // TODO FIXME (?) do port ctrls/clones?
+                        editable_part->setLenTick(i->new_partlen_or_tick);
+                        updateFlags |= SC_PART_MODIFIED;
+                        break;
+                  case UndoOp::ModifyPartLengthFrames: // TODO FIXME  FINDMICH frames deprecated!   do port ctrls/clones?
+                        editable_part->setLenFrame(i->new_partlen_or_tick);
                         updateFlags |= SC_PART_MODIFIED;
                         break;
                   case UndoOp::AddEvent:
-                        addEvent(i->nEvent, i->part);
+                        addEvent(i->nEvent, editable_part);
                         if(i->doCtrls)
-                          addPortCtrlEvents(i->nEvent, i->part, i->doClones);
+                          addPortCtrlEvents(i->nEvent, editable_part, i->doClones);
                         updateFlags |= SC_EVENT_INSERTED;
                         break;
                   case UndoOp::DeleteEvent:
                         if(i->doCtrls)
-                          removePortCtrlEvents(i->nEvent, i->part, i->doClones);
-                        deleteEvent(i->nEvent, i->part);
+                          removePortCtrlEvents(i->nEvent, editable_part, i->doClones);
+                        deleteEvent(i->nEvent, editable_part);
                         updateFlags |= SC_EVENT_REMOVED;
                         break;
                   case UndoOp::ModifyEvent:
                         if(i->doCtrls)
-                          removePortCtrlEvents(i->nEvent, i->part, i->doClones);
-                        changeEvent(i->nEvent, i->oEvent, i->part);
+                          removePortCtrlEvents(i->oEvent, editable_part, i->doClones);
+                        changeEvent(i->oEvent, i->nEvent, editable_part);
                         if(i->doCtrls)
-                          addPortCtrlEvents(i->oEvent, i->part, i->doClones);
+                          addPortCtrlEvents(i->nEvent, editable_part, i->doClones);
                         updateFlags |= SC_EVENT_MODIFIED;
                         break;
                   case UndoOp::AddTempo:
@@ -569,13 +696,13 @@ UndoOp::UndoOp()
   type=UndoOp::DoNothing;
 }
 
-UndoOp::UndoOp(UndoType type_)
-{
-	type = type_;
-}
-
 UndoOp::UndoOp(UndoType type_, int a_, int b_, int c_)
       {
+      assert(type_==AddKey || type_==DeleteKey ||
+             type_==AddTempo || type_==DeleteTempo ||
+             type_==AddSig || type_==DeleteSig ||
+             type_==ModifySongLen || type_==SwapTrack);
+      
       type = type_;
       a  = a_;
       b  = b_;
@@ -583,21 +710,56 @@ UndoOp::UndoOp(UndoType type_, int a_, int b_, int c_)
       }
 
 
-UndoOp::UndoOp(UndoType type_, int n, Track* track_)
+UndoOp::UndoOp(UndoType type_, int n, const Track* track_)
       {
+      assert(type_==AddTrack || type_==DeleteTrack);
+      assert(track_);
+      
       type    = type_;
       trackno = n;
       track  = track_;
       }
 
-UndoOp::UndoOp(UndoType type_, Part* part)
+UndoOp::UndoOp(UndoType type_, const Part* part_, unsigned old_len_or_tick, unsigned new_len_or_tick, bool, bool)
       {
+      assert(type_==AddPart || type_==DeletePart || type_==ModifyPartLength || type_==ModifyPartLengthFrames || type_==ModifyPartTick );
+      assert(part_);
+      
       type  = type_;
-      oPart = part;
+      part = part_;
+      old_partlen_or_tick=old_len_or_tick;
+      new_partlen_or_tick=new_len_or_tick;
       }
+      
+UndoOp::UndoOp(UndoType type_, const Part* part_, bool selected_, bool sel_old_)
+{
+    assert(type_==SelectPart);
+    assert(part_);
+    
+    type=type_;
+    part = part_;
+    selected=selected_;
+    selected_old=sel_old_;
+}
 
-UndoOp::UndoOp(UndoType type_, Event& oev, Event& nev, Part* part_, bool doCtrls_, bool doClones_)
+UndoOp::UndoOp(UndoType type_, const Part* part_, const Track* nTrack, const Track* oTrack)
+{
+    assert(type_==MovePartToTrack);
+    assert(part_);
+    assert(nTrack);
+    assert(oTrack);
+    
+    type=type_;
+    part = part_;
+    track=nTrack;
+    oldTrack=oTrack;
+}
+
+UndoOp::UndoOp(UndoType type_, const Event& nev, const Event& oev, const Part* part_, bool doCtrls_, bool doClones_)
       {
+      assert(type_==ModifyEvent);
+      assert(part_);
+      
       type   = type_;
       nEvent = nev;
       oEvent = oev;
@@ -606,35 +768,35 @@ UndoOp::UndoOp(UndoType type_, Event& oev, Event& nev, Part* part_, bool doCtrls
       doClones = doClones_;
       }
 
-UndoOp::UndoOp(UndoType type_, Event& nev, Part* part_, bool doCtrls_, bool doClones_)
+UndoOp::UndoOp(UndoType type_, const Event& nev, const Part* part_, bool doCtrls_, bool doClones_)
       {
+      assert(type_==DeleteEvent || type_==AddEvent);
+      assert(part_);
+      
       type   = type_;
       nEvent = nev;
       part   = part_;
       doCtrls = doCtrls_;
       doClones = doClones_;
       }
+      
+UndoOp::UndoOp(UndoType type_, const Event& nev, bool selected_, bool sel_old_)
+{
+    assert(type_==SelectEvent);
+    
+    type=type_;
+    nEvent = nev;
+    selected=selected_;
+    selected_old=sel_old_;
+}
 
-UndoOp::UndoOp(UndoType type_, Part* oPart_, Part* nPart_, bool doCtrls_, bool doClones_)
-      {
-      type  = type_;
-      oPart = oPart_;
-      nPart = nPart_;
-      doCtrls = doCtrls_;
-      doClones = doClones_;
-      }
-
-UndoOp::UndoOp(UndoType type_, int c, int ctrl_, int ov, int nv)
-      {
-      type    = type_;
-      channel = c;
-      ctrl    = ctrl_;
-      oVal    = ov;
-      nVal    = nv;
-      }
 
 UndoOp::UndoOp(UndoType type_, Marker* copyMarker_, Marker* realMarker_)
       {
+      assert(type_==ModifyMarker);
+      assert(copyMarker_);
+      assert(realMarker_);
+      
       type    = type_;
       realMarker  = realMarker_;
       copyMarker  = copyMarker_;
@@ -642,6 +804,8 @@ UndoOp::UndoOp(UndoType type_, Marker* copyMarker_, Marker* realMarker_)
 
 UndoOp::UndoOp(UndoType type_, const char* changedFile, const char* changeData, int startframe_, int endframe_)
       {
+      assert(type_==ModifyClip);
+      
       type = type_;
       filename   = changedFile;
       tmpwavfile = changeData;
@@ -649,18 +813,41 @@ UndoOp::UndoOp(UndoType type_, const char* changedFile, const char* changeData,
       endframe   = endframe_;
       }
 
-UndoOp::UndoOp(UndoOp::UndoType type_, Track* track_, const char* old_name, const char* new_name)
+UndoOp::UndoOp(UndoOp::UndoType type_, const Part* part_, const char* old_name, const char* new_name)
+{
+    assert(type_==ModifyPartName);
+    assert(part_);
+    assert(old_name);
+    assert(new_name);
+    
+    type=type_;
+    part=part_;
+    _oldName = new char[strlen(old_name) + 1];
+    _newName = new char[strlen(new_name) + 1];
+    strcpy(_oldName, old_name);
+    strcpy(_newName, new_name);
+}
+
+UndoOp::UndoOp(UndoOp::UndoType type_, const Track* track_, const char* old_name, const char* new_name)
 {
+  assert(type_==ModifyTrackName);
+  assert(track_);
+  assert(old_name);
+  assert(new_name);    
+    
   type = type_;
-  _renamedTrack = track_;
+  track = track_;
   _oldName = new char[strlen(old_name) + 1];
   _newName = new char[strlen(new_name) + 1];
   strcpy(_oldName, old_name);
   strcpy(_newName, new_name);
 }
 
-UndoOp::UndoOp(UndoOp::UndoType type_, Track* track_, int old_chan, int new_chan)
+UndoOp::UndoOp(UndoOp::UndoType type_, const Track* track_, int old_chan, int new_chan)
 {
+  assert(type_==ModifyTrackChannel);
+  assert(track_);
+  
   type = type_;
   _propertyTrack = track_;
   _oldPropValue = old_chan;
@@ -688,37 +875,46 @@ void Song::addUndo(UndoOp i)
       }
 
 //---------------------------------------------------------
-//   doUndo1
+//   revertOperationGroup1
 //    non realtime context
 //    return true if nothing to do
 //---------------------------------------------------------
 
-bool Song::doUndo1()
+void Song::revertOperationGroup1(Undo& operations)
       {
-      if (undoList->empty())
-            return true;
-      Undo& u = undoList->back();
-      for (riUndoOp i = u.rbegin(); i != u.rend(); ++i) {
+      for (riUndoOp i = operations.rbegin(); i != operations.rend(); ++i) {
+            Track* editable_track = const_cast<Track*>(i->track);
+            Track* editable_property_track = const_cast<Track*>(i->_propertyTrack);
+            Part* editable_part = const_cast<Part*>(i->part);
             switch(i->type) {
+                  case UndoOp::SelectPart:
+                        editable_part->setSelected(i->selected_old);
+                        updateFlags |= SC_SELECTION;
+                        break;
+                  case UndoOp::SelectEvent:
+                        i->nEvent.setSelected(i->selected_old);
+                        updateFlags |= SC_SELECTION;
+                        break;
+                        
                   case UndoOp::AddTrack:
-                        removeTrack1(i->track);
+                        removeTrack1(editable_track);
                         break;
                   case UndoOp::DeleteTrack:
-                        insertTrack1(i->track, i->trackno);
+                        insertTrack1(editable_track, i->trackno);
 
                         // FIXME: Would like to put this part in Undo2, but indications
                         //  elsewhere are that (dis)connecting jack routes must not be
                         //  done in the realtime thread. The result is that we get a few
                         //  "PANIC Process init: No buffer from audio device" messages
                         //  before the routes are (dis)connected. So far seems to do no harm though...
-                        switch(i->track->type())
+                        switch(editable_track->type())
                         {
                               case Track::AUDIO_OUTPUT:
                               case Track::AUDIO_INPUT:
-                                      connectJackRoutes((AudioTrack*)i->track, false);
+                                      connectJackRoutes((AudioTrack*)editable_track, false);
                                     break;
                               //case Track::AUDIO_SOFTSYNTH: DELETETHIS 4
-                                      //SynthI* si = (SynthI*)i->track;
+                                      //SynthI* si = (SynthI*)editable_track;
                                       //si->synth()->init(
                               //      break;
                               default:
@@ -727,16 +923,16 @@ bool Song::doUndo1()
 
                         break;
                   case UndoOp::ModifyTrackName:
-                          i->_renamedTrack->setName(i->_oldName);
+                          editable_track->setName(i->_oldName);
                           updateFlags |= SC_TRACK_MODIFIED;
                         break;
                   case UndoOp::ModifyClip:
                         MusECore::SndFile::applyUndoFile(i->filename, i->tmpwavfile, i->startframe, i->endframe);
                         break;
                   case UndoOp::ModifyTrackChannel:
-                        if (i->_propertyTrack->isMidiTrack()) 
+                        if (editable_property_track->isMidiTrack()) 
                         {
-                          MusECore::MidiTrack* mt = dynamic_cast<MusECore::MidiTrack*>(i->_propertyTrack);
+                          MusECore::MidiTrack* mt = dynamic_cast<MusECore::MidiTrack*>(editable_property_track);
                           if (mt == 0 || mt->type() == MusECore::Track::DRUM)
                             break;
                           if (i->_oldPropValue != mt->outChannel()) 
@@ -756,9 +952,9 @@ bool Song::doUndo1()
                         }
                         else
                         {
-                            if(i->_propertyTrack->type() != MusECore::Track::AUDIO_SOFTSYNTH)
+                            if(editable_property_track->type() != MusECore::Track::AUDIO_SOFTSYNTH)
                             {
-                              MusECore::AudioTrack* at = dynamic_cast<MusECore::AudioTrack*>(i->_propertyTrack);
+                              MusECore::AudioTrack* at = dynamic_cast<MusECore::AudioTrack*>(editable_property_track);
                               if (at == 0)
                                 break;
                               if (i->_oldPropValue != at->channels()) {
@@ -773,24 +969,26 @@ bool Song::doUndo1()
                         break;
                   }
             }
-      return false;
+      return;
       }
 
 //---------------------------------------------------------
-//   doUndo3
+//   revertOperationGroup3
 //    non realtime context
 //---------------------------------------------------------
 
-void Song::doUndo3()
+void Song::revertOperationGroup3(Undo& operations)
       {
-      Undo& u = undoList->back();
-      for (riUndoOp i = u.rbegin(); i != u.rend(); ++i) {
+      for (riUndoOp i = operations.rbegin(); i != operations.rend(); ++i) {
+            Track* editable_track = const_cast<Track*>(i->track);
+// uncomment if needed            Track* editable_property_track = const_cast<Track*>(i->_propertyTrack);
+// uncomment if needed            Part* editable_part = const_cast<Part*>(i->part);
             switch(i->type) {
                   case UndoOp::AddTrack:
-                        removeTrack3(i->track);
+                        removeTrack3(editable_track);
                         break;
                   case UndoOp::DeleteTrack:
-                        insertTrack3(i->track, i->trackno);
+                        insertTrack3(editable_track, i->trackno);
                         break;
                   case UndoOp::ModifyMarker:
                         {
@@ -810,36 +1008,42 @@ void Song::doUndo3()
                         break;
                   }
             }
-      redoList->push_back(u); // put item on redo list
-      undoList->pop_back();
-      emit sigDirty();
       }
 
 //---------------------------------------------------------
-//   doRedo1
+//   executeOperationGroup1
 //    non realtime context
 //    return true if nothing to do
 //---------------------------------------------------------
 
-bool Song::doRedo1()
+void Song::executeOperationGroup1(Undo& operations)
       {
-      if (redoList->empty())
-            return true;
-      Undo& u = redoList->back();
-      for (iUndoOp i = u.begin(); i != u.end(); ++i) {
+      for (iUndoOp i = operations.begin(); i != operations.end(); ++i) {
+            Track* editable_track = const_cast<Track*>(i->track);
+            Track* editable_property_track = const_cast<Track*>(i->_propertyTrack);
+            Part* editable_part = const_cast<Part*>(i->part);
             switch(i->type) {
+                  case UndoOp::SelectPart:
+                        editable_part->setSelected(i->selected);
+                        updateFlags |= SC_SELECTION;
+                        break;
+                  case UndoOp::SelectEvent:
+                        i->nEvent.setSelected(i->selected);
+                        updateFlags |= SC_SELECTION;
+                        break;
+                        
                   case UndoOp::AddTrack:
-                        insertTrack1(i->track, i->trackno);
+                        insertTrack1(editable_track, i->trackno);
 
                         // FIXME: See comments in Undo1.
-                        switch(i->track->type())
+                        switch(editable_track->type())
                         {
                               case Track::AUDIO_OUTPUT:
                               case Track::AUDIO_INPUT:
-                                      connectJackRoutes((AudioTrack*)i->track, false);
+                                      connectJackRoutes((AudioTrack*)editable_track, false);
                                     break;
                               //case Track::AUDIO_SOFTSYNTH: DELETETHIS 4
-                                      //SynthI* si = (SynthI*)i->track;
+                                      //SynthI* si = (SynthI*)editable_track;
                                       //si->synth()->init(
                               //      break;
                               default:
@@ -848,19 +1052,19 @@ bool Song::doRedo1()
 
                         break;
                   case UndoOp::DeleteTrack:
-                        removeTrack1(i->track);
+                        removeTrack1(editable_track);
                         break;
                   case UndoOp::ModifyTrackName:
-                          i->_renamedTrack->setName(i->_newName);
+                          editable_track->setName(i->_newName);
                           updateFlags |= SC_TRACK_MODIFIED;
                         break;
                   case UndoOp::ModifyClip:
                         MusECore::SndFile::applyUndoFile(i->filename, i->tmpwavfile, i->startframe, i->endframe);
                         break;
                   case UndoOp::ModifyTrackChannel:
-                        if (i->_propertyTrack->isMidiTrack()) 
+                        if (editable_property_track->isMidiTrack()) 
                         {
-                          MusECore::MidiTrack* mt = dynamic_cast<MusECore::MidiTrack*>(i->_propertyTrack);
+                          MusECore::MidiTrack* mt = dynamic_cast<MusECore::MidiTrack*>(editable_property_track);
                           if (mt == 0 || mt->type() == MusECore::Track::DRUM)
                             break;
                           if (i->_newPropValue != mt->outChannel()) 
@@ -880,9 +1084,9 @@ bool Song::doRedo1()
                         }
                         else
                         {
-                            if(i->_propertyTrack->type() != MusECore::Track::AUDIO_SOFTSYNTH)
+                            if(editable_property_track->type() != MusECore::Track::AUDIO_SOFTSYNTH)
                             {
-                              MusECore::AudioTrack* at = dynamic_cast<MusECore::AudioTrack*>(i->_propertyTrack);
+                              MusECore::AudioTrack* at = dynamic_cast<MusECore::AudioTrack*>(editable_property_track);
                               if (at == 0)
                                 break;
                               if (i->_newPropValue != at->channels()) {
@@ -897,24 +1101,25 @@ bool Song::doRedo1()
                         break;
                   }
             }
-      return false;
       }
 
 //---------------------------------------------------------
-//   doRedo3
+//   executeOperationGroup3
 //    non realtime context
 //---------------------------------------------------------
 
-void Song::doRedo3()
+void Song::executeOperationGroup3(Undo& operations)
       {
-      Undo& u = redoList->back();
-      for (iUndoOp i = u.begin(); i != u.end(); ++i) {
+      for (iUndoOp i = operations.begin(); i != operations.end(); ++i) {
+            Track* editable_track = const_cast<Track*>(i->track);
+// uncomment if needed            Track* editable_property_track = const_cast<Track*>(i->_propertyTrack);
+// uncomment if needed            Part* editable_part = const_cast<Part*>(i->part);
             switch(i->type) {
                   case UndoOp::AddTrack:
-                        insertTrack3(i->track, i->trackno);
+                        insertTrack3(editable_track, i->trackno);
                         break;
                   case UndoOp::DeleteTrack:
-                        removeTrack3(i->track);
+                        removeTrack3(editable_track);
                         break;
                   case UndoOp::ModifyMarker:
                         {
@@ -933,9 +1138,6 @@ void Song::doRedo3()
                         break;
                   }
             }
-      undoList->push_back(u); // put item on undo list
-      redoList->pop_back();
-      emit sigDirty();
       }
 
 
diff --git a/muse2/muse/undo.h b/muse2/muse/undo.h
index 2f582d8e..f83ce491 100644
--- a/muse2/muse/undo.h
+++ b/muse2/muse/undo.h
@@ -46,8 +46,9 @@ extern std::list<QString> temporaryWavFiles; //!< Used for storing all tmp-files
 struct UndoOp {
       enum UndoType {
             AddTrack, DeleteTrack,
-            AddPart,  DeletePart,  ModifyPart,
-            AddEvent, DeleteEvent, ModifyEvent,
+            AddPart,  DeletePart,  ModifyPartTick, ModifyPartLength, ModifyPartLengthFrames, /* FINDMICH FIXME frames are to be deprecated */ ModifyPartName, SelectPart,
+            MovePartToTrack,
+            AddEvent, DeleteEvent, ModifyEvent, SelectEvent,
             AddTempo, DeleteTempo,
             AddSig,   DeleteSig,
             AddKey,   DeleteKey,
@@ -67,15 +68,9 @@ struct UndoOp {
                   int c;
                   };
             struct {
-                  Track* track;
-                  int trackno;
-                  };
-            struct {
-                  Part* oPart;
-                  Part* nPart;
-                  };
-            struct {
-                  Part* part; // this part is only relevant for EVENT operations, NOT for part ops!
+                  const Part* part;
+                  unsigned old_partlen_or_tick; // FIXME FINDMICHJETZT XTicks!!
+                  unsigned new_partlen_or_tick;
                   };
             struct {
                   int channel;
@@ -90,50 +85,72 @@ struct UndoOp {
                   const char* tmpwavfile; //!< The file with the changed data
                   };
             struct {
-                  Marker* realMarker;
+                  Marker* realMarker; 
                   Marker* copyMarker;
                 };
             struct {
-                  Track* _renamedTrack;
-                  char* _oldName;
-                  char* _newName;
-                };
-            struct {
-                  Track* _propertyTrack;
+                  const Track* _propertyTrack;
                   int _oldPropValue;
                   int _newPropValue;
                 };
             };
+
+      char* _oldName;
+      char* _newName;
       Event oEvent;
       Event nEvent;
+      bool selected;
+      bool selected_old;
       bool doCtrls;
       bool doClones;
+      const Track* track;
+      const Track* oldTrack;
+      int trackno;
       
       const char* typeName();
       void dump();
       
       UndoOp();
       UndoOp(UndoType type, int a, int b, int c=0);
-      UndoOp(UndoType type, int n, Track* track);
-      UndoOp(UndoType type, Part* part);
-      UndoOp(UndoType type, Event& oev, Event& nev, Part* part, bool doCtrls, bool doClones);
-      UndoOp(UndoType type, Event& nev, Part* part, bool doCtrls, bool doClones);
-      UndoOp(UndoType type, Part* oPart, Part* nPart, bool doCtrls, bool doClones);
-      UndoOp(UndoType type, int c, int ctrl, int ov, int nv);
+      UndoOp(UndoType type, int n, const Track* track);
+      UndoOp(UndoType type, const Part* part, unsigned old_len_or_tick=-1, unsigned new_len_or_tick=-1, bool doCtrls=false, bool doClones=false); // FIXME these bools are UNUSED!!. XTICKS!
+      UndoOp(UndoType type, const Part* part, const char* old_name, const char* new_name);
+      UndoOp(UndoType type, const Part* part, bool selected, bool selected_old);
+      UndoOp(UndoType type, const Part* part, const Track* nTrack, const Track* oTrack);
+      UndoOp(UndoType type, const Event& nev, const Event& oev, const Part* part, bool doCtrls, bool doClones);
+      UndoOp(UndoType type, const Event& nev, const Part* part, bool doCtrls, bool doClones);
+      UndoOp(UndoType type, const Event& nev, bool selected, bool selected_old);
       UndoOp(UndoType type, const char* changedFile, const char* changeData, int startframe, int endframe);
       UndoOp(UndoType type, Marker* copyMarker, Marker* realMarker);
-      UndoOp(UndoType type, Track* track, const char* old_name, const char* new_name);
-      UndoOp(UndoType type, Track* track, int old_chan, int new_chan);
-      UndoOp(UndoType type);
+      UndoOp(UndoType type, const Track* track, const char* old_name, const char* new_name);
+      UndoOp(UndoType type, const Track* track, int old_chan, int new_chan);
 };
 
 class Undo : public std::list<UndoOp> {
    public:
+      Undo() : std::list<UndoOp>() { combobreaker=false; }
+      Undo(const Undo& other) : std::list<UndoOp>(other) { this->combobreaker=other.combobreaker; }
+      Undo& operator=(const Undo& other) { std::list<UndoOp>::operator=(other); this->combobreaker=other.combobreaker; return *this;}
+
       bool empty() const;
+      
+      
+      /** if set, forbid merging (below).
+       *  Defaults to false */
+      bool combobreaker; 
+      
+      /** is possible, merges itself and other by appending
+       *  all contents of other at this->end().
+       *  returns true if merged, false otherwise.
+       *  in case of success, the caller has to ensure that
+       *  other is deleted from the UndoList. */
+      bool merge_combo(const Undo& other);
 };
 
 typedef Undo::iterator iUndoOp;
 typedef Undo::reverse_iterator riUndoOp;
+typedef Undo::const_iterator ciUndoOp;
+typedef Undo::const_reverse_iterator criUndoOp;
 
 class UndoList : public std::list<Undo> {
    protected:
diff --git a/muse2/muse/wave.cpp b/muse2/muse/wave.cpp
index 8c647685..9bf26753 100644
--- a/muse2/muse/wave.cpp
+++ b/muse2/muse/wave.cpp
@@ -826,11 +826,11 @@ bool SndFile::checkCopyOnWrite()
     PartList* pl = (*it)->parts();
     for(ciPart ip = pl->begin(); ip != pl->end(); ++ip)
     {
-      EventList* el = ip->second->events();
+      const EventList& el = ip->second->events();
       // We are looking for active independent non-clone parts
-      if(el->arefCount() > 1)
+      if(ip->second->hasClones())
         continue;
-      for(ciEvent ie = el->begin(); ie != el->end(); ++ie)
+      for(ciEvent ie = el.begin(); ie != el.end(); ++ie)
       {
         if(ie->second.type() != Wave)
           continue;
@@ -1114,7 +1114,10 @@ void Song::cmdAddRecordedWave(MusECore::WaveTrack* track, MusECore::Pos s, MusEC
       event.setLenFrame(e.frame() - s.frame());
       part->addEvent(event);
 
-      MusEGlobal::song->cmdAddPart(part);
+      // TODO FIXME that's ugly (flo)
+      addPart(part);
+      addUndo(UndoOp(UndoOp::AddPart, part));
+      updateFlags = SC_PART_INSERTED;
 
       if (MusEGlobal::song->len() < etick)
             MusEGlobal::song->setLen(etick);
diff --git a/muse2/muse/waveedit/wavecanvas.cpp b/muse2/muse/waveedit/wavecanvas.cpp
index 95ecd250..db886bce 100644
--- a/muse2/muse/waveedit/wavecanvas.cpp
+++ b/muse2/muse/waveedit/wavecanvas.cpp
@@ -79,7 +79,7 @@ namespace MusEGui {
 //   WEvent
 //---------------------------------------------------------
 
-WEvent::WEvent(MusECore::Event& e, MusECore::Part* p, int height) : MusEGui::CItem(e, p)
+WEvent::WEvent(const MusECore::Event& e, MusECore::Part* p, int height) : MusEGui::CItem(e, p)
       {
       unsigned frame = e.frame() + p->frame();
       setPos(QPoint(frame, 0));
@@ -93,7 +93,7 @@ WEvent::WEvent(MusECore::Event& e, MusECore::Part* p, int height) : MusEGui::CIt
 //   addItem
 //---------------------------------------------------------
 
-CItem* WaveCanvas::addItem(MusECore::Part* part, MusECore::Event& event)
+CItem* WaveCanvas::addItem(MusECore::Part* part, const MusECore::Event& event)
       {
       if (signed(event.frame())<0) {
             printf("ERROR: trying to add event before current part!\n");
@@ -183,9 +183,8 @@ void WaveCanvas::songChanged(MusECore::SongChangedFlags_t flags)
                   if (esample > endSample)
                         endSample = esample;
 
-                  MusECore::EventList* el = part->events();
-                  for (MusECore::iEvent i = el->begin(); i != el->end(); ++i) {
-                        MusECore::Event e = i->second;
+                  for (MusECore::ciEvent i = part->events().begin(); i != part->events().end(); ++i) {
+                        const MusECore::Event& e = i->second;
                         // Do not add events which are past the end of the part.
                         if(e.frame() > len)      
                           break;
@@ -578,9 +577,9 @@ void WaveCanvas::draw(QPainter& p, const QRect& r)
           if(ci->isSelected()) 
             list4.push_back(ci);
           // Draw clone parts, and parts with hidden events, in front of others all except selected.
-          //else if(ci->event().empty() && (ci->part()->events()->arefCount() > 1 || ci->part()->cachedHasHiddenEvents()))
+          //else if(ci->event().empty() && (ci->part()->hasClones() || ci->part()->cachedHasHiddenEvents()))
           // Draw clone parts in front of others all except selected.
-          //else if(ci->event().empty() && (ci->part()->events()->arefCount() > 1))
+          //else if(ci->event().empty() && ci->part()->hasClones())
           //  list3.push_back(ci);
           else  
             // Draw unselected parts.
@@ -1327,9 +1326,9 @@ MusECore::Undo WaveCanvas::moveCanvasItems(MusEGui::CItemList& items, int /*dp*/
     MusECore::Part* opart = ip2c->first;
     if (opart->hasHiddenEvents())
     {
-                        forbidden=true;
-                        break;
-                }
+        forbidden=true;
+        break;
+    }
   }    
 
         
@@ -1478,7 +1477,6 @@ void WaveCanvas::newItem(MusEGui::CItem* item, bool noSnap)
         
         if (diff > 0)// part must be extended?
         {
-              //schedule_resize_all_same_len_clone_parts(part, event.endTick(), operations);
               schedule_resize_all_same_len_clone_parts(part, event.endFrame(), operations);
               printf("newItem: extending\n");
         }
@@ -1686,11 +1684,11 @@ void WaveCanvas::waveCmd(int cmd)
                   if (part == 0)
                         break;
 
-                  MusECore::EventList* el = part->events();
+                  const MusECore::EventList& el = part->events();
                   MusECore::Undo operations;
 
                   std::list <MusECore::Event> elist;
-                  for (MusECore::iEvent e = el->lower_bound(pos[0] - part->tick()); e != el->end(); ++e)
+                  for (MusECore::ciEvent e = el.lower_bound(pos[0] - part->tick()); e != el.end(); ++e)
                         elist.push_back((MusECore::Event)e->second);
                   for (std::list<MusECore::Event>::iterator i = elist.begin(); i != elist.end(); ++i) {
                         MusECore::Event event = *i;
@@ -1714,10 +1712,10 @@ void WaveCanvas::waveCmd(int cmd)
                         break;
                   
                   MusECore::Undo operations;
-                  MusECore::EventList* el = part->events();
+                  const MusECore::EventList& el = part->events();
 
                   std::list<MusECore::Event> elist;
-                  for (MusECore::iEvent e = el->lower_bound(pos[0]); e != el->end(); ++e)
+                  for (MusECore::ciEvent e = el.lower_bound(pos[0]); e != el.end(); ++e)
                         elist.push_back((MusECore::Event)e->second);
                   for (std::list<MusECore::Event>::iterator i = elist.begin(); i != elist.end(); ++i) {
                         MusECore::Event event = *i;
@@ -1927,17 +1925,17 @@ void WaveCanvas::cmd(int cmd)
                       tempPart->setPos(MusEGlobal::song->lpos());
                       tempPart->setLenTick(MusEGlobal::song->rpos() - MusEGlobal::song->lpos());
                       // loop through the events and set them accordingly
-                      for (MusECore::iEvent iWaveEvent = origPart->events()->begin(); iWaveEvent != origPart->events()->end(); iWaveEvent++)
+                      for (MusECore::ciEvent iWaveEvent = origPart->events().begin(); iWaveEvent != origPart->events().end(); iWaveEvent++)
                       {
                           // TODO: handle multiple events correctly,
                           // the math for subsequent events isn't correct
-                          MusECore::Event &ev = iWaveEvent->second;
+                          const MusECore::Event& ev = iWaveEvent->second;
                           MusECore::Event *newEvent = new MusECore::Event(ev.clone());
                           newEvent->setSpos(ev.spos() + frameDistance);
                           newEvent->setLenTick(MusEGlobal::song->rpos() - MusEGlobal::song->lpos());
                           tempPart->addEvent(*newEvent);
                       }
-                      std::set<MusECore::Part*> partList;
+                      std::set<const MusECore::Part*> partList;
                       partList.insert(tempPart);
 
                       QMimeData *mimeData =  MusECore::parts_to_mime(partList);
@@ -1993,10 +1991,9 @@ MusECore::WaveSelectionList WaveCanvas::getSelection(unsigned startpos, unsigned
             MusECore::WavePart* wp = (MusECore::WavePart*)(ip->second);
             unsigned part_offset = wp->frame();
             
-            MusECore::EventList* el = wp->events();
-            //printf("eventlist length=%d\n",el->size());
+            const MusECore::EventList& el = wp->events();
 
-            for (MusECore::iEvent e = el->begin(); e != el->end(); ++e) {
+            for (MusECore::ciEvent e = el.begin(); e != el.end(); ++e) {
                   MusECore::Event event  = e->second;
                   if (event.empty())
                         continue;
@@ -2587,7 +2584,7 @@ void WaveCanvas::curPartChanged()
 void WaveCanvas::modifySelected(MusEGui::NoteInfo::ValType type, int val, bool delta_mode)
       {
       // TODO: New WaveCanvas: Convert this routine to frames and remove unneeded operations. 
-      QList< QPair<MusECore::EventList*,MusECore::Event> > already_done;
+      QList< QPair<int,MusECore::Event> > already_done;
       MusEGlobal::audio->msgIdle(true);
       MusEGlobal::song->startUndo();
       for (MusEGui::iCItem i = items.begin(); i != items.end(); ++i) {
@@ -2600,7 +2597,7 @@ void WaveCanvas::modifySelected(MusEGui::NoteInfo::ValType type, int val, bool d
 
             MusECore::WavePart* part = (MusECore::WavePart*)(e->part());
             
-            if (already_done.contains(QPair<MusECore::EventList*,MusECore::Event>(part->events(), event)))
+            if (already_done.contains(QPair<int,MusECore::Event>(part->clonemaster_sn(), event)))
               continue;
             
             MusECore::Event newEvent = event.clone();
@@ -2670,7 +2667,7 @@ void WaveCanvas::modifySelected(MusEGui::NoteInfo::ValType type, int val, bool d
             // Indicate do not do port controller values and clone parts. 
             MusEGlobal::song->addUndo(MusECore::UndoOp(MusECore::UndoOp::ModifyEvent, newEvent, event, part, false, false));
 
-            already_done.append(QPair<MusECore::EventList*,MusECore::Event>(part->events(), event));
+            already_done.append(QPair<int,MusECore::Event>(part->clonemaster_sn(), event));
             }
       MusEGlobal::song->endUndo(SC_EVENT_MODIFIED);
       MusEGlobal::audio->msgIdle(false);
diff --git a/muse2/muse/waveedit/wavecanvas.h b/muse2/muse/waveedit/wavecanvas.h
index 10f75291..63979915 100644
--- a/muse2/muse/waveedit/wavecanvas.h
+++ b/muse2/muse/waveedit/wavecanvas.h
@@ -64,7 +64,7 @@ namespace MusEGui {
 
 class WEvent : public CItem {
    public:
-      WEvent(MusECore::Event& e, MusECore::Part* p, int height);
+      WEvent(const MusECore::Event& e, MusECore::Part* p, int height);
       };
 
 //---------------------------------------------------------
@@ -124,7 +124,7 @@ class WaveCanvas : public EventCanvas {
       virtual void dragEnterEvent(QDragEnterEvent* event);
       virtual void dragMoveEvent(QDragMoveEvent*);
       virtual void dragLeaveEvent(QDragLeaveEvent*);
-      virtual CItem* addItem(MusECore::Part*, MusECore::Event&);
+      virtual CItem* addItem(MusECore::Part*, const MusECore::Event&);
 
       int y2pitch(int) const;
       int pitch2y(int) const;
diff --git a/muse2/muse/waveedit/waveview.cpp b/muse2/muse/waveedit/waveview.cpp
index 3e3ea057..2cb63dc5 100644
--- a/muse2/muse/waveedit/waveview.cpp
+++ b/muse2/muse/waveedit/waveview.cpp
@@ -119,9 +119,8 @@ void WaveView::pdraw(QPainter& p, const QRect& rr)
             int channels = wp->track()->channels();
             int px = wp->frame();
 
-            MusECore::EventList* el = wp->events();
-            for (MusECore::iEvent e = el->begin(); e != el->end(); ++e) {
-                  MusECore::Event event  = e->second;
+            for (MusECore::ciEvent e = wp->events().begin(); e != wp->events().end(); ++e) {
+                  const MusECore::Event event&  = e->second;
                   if (event.empty())
                         continue;
                   MusECore::SndFileR f = event.sndFile();
diff --git a/muse2/muse/waveevent.cpp b/muse2/muse/waveevent.cpp
index 38ae10c6..24be2d01 100644
--- a/muse2/muse/waveevent.cpp
+++ b/muse2/muse/waveevent.cpp
@@ -53,16 +53,25 @@ WaveEventBase::WaveEventBase(EventType t)
 //   WaveEventBase::clone
 //---------------------------------------------------------
 
-EventBase* WaveEventBase::clone() 
+EventBase* WaveEventBase::clone() const
 { 
   return new WaveEventBase(*this); 
 }
 
+bool WaveEventBase::isSimilarTo(const EventBase& other_) const
+{
+	const WaveEventBase* other = dynamic_cast<const WaveEventBase*>(&other_);
+	if (other==NULL) // dynamic cast hsa failed: "other_" is not of type WaveEventBase.
+		return false;
+	
+	return f.dirPath()==other->f.dirPath() && _spos==other->_spos && this->PosLen::operator==(*other);
+}
+
 //---------------------------------------------------------
 //   WaveEvent::mid
 //---------------------------------------------------------
 
-EventBase* WaveEventBase::mid(unsigned b, unsigned e)
+EventBase* WaveEventBase::mid(unsigned b, unsigned e) const
       {
       WaveEventBase* ev = new WaveEventBase(*this);
       unsigned fr = frame();
diff --git a/muse2/muse/waveevent.h b/muse2/muse/waveevent.h
index e814fe3d..d11803c7 100644
--- a/muse2/muse/waveevent.h
+++ b/muse2/muse/waveevent.h
@@ -44,15 +44,17 @@ class WaveEventBase : public EventBase {
       int _spos;            // start sample position in WaveFile
       bool deleted;
 
-      virtual EventBase* clone();
+      virtual EventBase* clone() const;
 
    public:
       WaveEventBase(EventType t);
       virtual ~WaveEventBase() {}
+      
+      virtual bool isSimilarTo(const EventBase& other) const;
 
       virtual void read(Xml&);
       virtual void write(int, Xml&, const Pos& offset, bool forcePath = false) const;
-      virtual EventBase* mid(unsigned, unsigned);
+      virtual EventBase* mid(unsigned, unsigned) const;
       
       virtual void dump(int n = 0) const;
 
diff --git a/muse2/muse/wavetrack.cpp b/muse2/muse/wavetrack.cpp
index 363f8966..f21992a6 100644
--- a/muse2/muse/wavetrack.cpp
+++ b/muse2/muse/wavetrack.cpp
@@ -60,27 +60,11 @@ void WaveTrack::internal_assign(const Track& t, int flags)
         const PartList* pl = t.cparts();
         for (ciPart ip = pl->begin(); ip != pl->end(); ++ip) {
               Part* spart = ip->second;
-              bool clone = spart->events()->arefCount() > 1;
-              // This increments aref count if cloned, and chains clones.
-              // It also gives the new part a new serial number.
-              Part* dpart = newPart(spart, clone);
-              if(!clone) {
-                    // Copy Events
-                    MusECore::EventList* se = spart->events();
-                    MusECore::EventList* de = dpart->events();
-                    for (MusECore::iEvent i = se->begin(); i != se->end(); ++i) {
-                          MusECore::Event oldEvent = i->second;
-                          MusECore::Event ev = oldEvent.clone();
-                          de->add(ev);
-                          }
-                    }
-
-              // TODO: Should we include the parts in the undo?
-              //      dpart->events()->incARef(-1); // the later MusEGlobal::song->applyOperationGroup() will increment it
-              //                                    // so we must decrement it first :/
-              //      // These will not increment ref count, and will not chain clones...
-              //      // DELETETHIS: is the above comment still correct (by flo93)? i doubt it!
-              //      operations.push_back(MusECore::UndoOp(MusECore::UndoOp::AddPart,dpart));
+              Part* dpart;
+              if (spart->hasClones())
+                  dpart = spart->createNewClone();
+              else
+                  dpart = spart->duplicate();
               
               parts()->add(dpart);
               }
@@ -127,8 +111,7 @@ void WaveTrack::fetchData(unsigned pos, unsigned samples, float** bp, bool doSee
               if (pos >= p_epos)
                 continue;
   
-              EventList* events = part->events();
-              for (iEvent ie = events->begin(); ie != events->end(); ++ie) {
+              for (iEvent ie = part->nonconst_events().begin(); ie != part->nonconst_events().end(); ++ie) {
                     Event& event = ie->second;
                     unsigned e_spos  = event.frame() + p_spos;
                     unsigned nn      = event.lenFrame();
@@ -201,11 +184,11 @@ void WaveTrack::read(Xml& xml)
             switch (token) {
                   case Xml::Error:
                   case Xml::End:
-                        return;
+                        goto out_of_WaveTrackRead_forloop;
                   case Xml::TagStart:
                         if (tag == "part") {
                               Part* p = 0;
-                              p = readXmlPart(xml, this);
+                              p = Part::readFromXml(xml, this);
                               if(p)
                                 parts()->add(p);
                               }
@@ -217,12 +200,14 @@ void WaveTrack::read(Xml& xml)
                   case Xml::TagEnd:
                         if (tag == "wavetrack") {
                               mapRackPluginsToControllers();
-                              return;
+                              goto out_of_WaveTrackRead_forloop;
                               }
                   default:
                         break;
                   }
             }
+out_of_WaveTrackRead_forloop:
+      chainTrackParts(this);
       }
 
 //---------------------------------------------------------
@@ -231,7 +216,16 @@ void WaveTrack::read(Xml& xml)
 
 Part* WaveTrack::newPart(Part*p, bool clone)
       {
-      WavePart* part = clone ? new WavePart(this, p->events()) : new WavePart(this);
+      WavePart* part;
+      if (clone)
+      {
+            part = (WavePart*)p->createNewClone();
+            part->setTrack(this);
+      }
+      else
+            part = new WavePart(this);
+      
+      
       if (p) {
             part->setName(p->name());
             part->setColorIndex(p->colorIndex());
@@ -240,9 +234,6 @@ Part* WaveTrack::newPart(Part*p, bool clone)
             part->setMute(p->mute());
             }
       
-      if(clone)
-        chainClone(p, part);
-      
       return part;
       }
 
diff --git a/muse2/muse/widgets/mtrackinfo.cpp b/muse2/muse/widgets/mtrackinfo.cpp
index 09d45577..a73eb212 100644
--- a/muse2/muse/widgets/mtrackinfo.cpp
+++ b/muse2/muse/widgets/mtrackinfo.cpp
@@ -682,18 +682,11 @@ void MidiTrackInfo::iOutputChannelChanged(int channel)
       MusECore::MidiTrack* track = (MusECore::MidiTrack*)selected;
       if (channel != track->outChannel()) {
             ++_blockHeartbeatCount;
-            // Changed by T356.
-            //track->setOutChannel(channel);
             MusEGlobal::audio->msgIdle(true);
-            //audio->msgSetTrackOutChannel(track, channel);
             track->setOutChanAndUpdate(channel);
             MusEGlobal::audio->msgIdle(false);
             
-            // may result in adding/removing mixer strip:
-            //MusEGlobal::song->update(-1);
-            //MusEGlobal::song->update(SC_MIDI_TRACK_PROP);
             MusEGlobal::audio->msgUpdateSoloStates();                   // p4.0.14
-            //MusEGlobal::song->update(SC_MIDI_TRACK_PROP | SC_ROUTE);  //
             MusEGlobal::song->update(SC_MIDI_TRACK_PROP);               //
             --_blockHeartbeatCount;
             }
@@ -714,16 +707,11 @@ void MidiTrackInfo::iOutputPortChanged(int index)
       if (port_num == track->outPort())
             return;
       ++_blockHeartbeatCount;
-      // Changed by T356.
-      //track->setOutPort(port_num);
       MusEGlobal::audio->msgIdle(true);
-      //audio->msgSetTrackOutPort(track, port_num);
       track->setOutPortAndUpdate(port_num);
       MusEGlobal::audio->msgIdle(false);
       
-      //MusEGlobal::song->update(SC_MIDI_TRACK_PROP);  
       MusEGlobal::audio->msgUpdateSoloStates();                   // p4.0.14
-      //MusEGlobal::song->update(SC_MIDI_TRACK_PROP | SC_ROUTE);  //
       MusEGlobal::song->update(SC_MIDI_TRACK_PROP);               //
       --_blockHeartbeatCount;
       }
diff --git a/muse2/muse/widgets/utils.cpp b/muse2/muse/widgets/utils.cpp
index ab1d74fd..687c76e4 100644
--- a/muse2/muse/widgets/utils.cpp
+++ b/muse2/muse/widgets/utils.cpp
@@ -532,7 +532,7 @@ int get_paste_len()
                         if (tag == "part")
                               {
                               Part* p = 0;
-                              p = readXmlPart(xml, NULL, false, false);
+                              p = Part::readFromXml(xml, NULL, false, false);
 
                               if (p)
                                     {
@@ -542,7 +542,7 @@ int get_paste_len()
                                     if (p->endTick() > end_tick)
                                           end_tick=p->endTick();
                                     
-                                    unchainClone(p);
+                                    p->unchainClone(); // just for safety; shouldn't be chained anyway.
                                     delete p;
                                     }
                               }