diff --git a/engine/api.py b/engine/api.py
index 305afa0..409dff1 100644
--- a/engine/api.py
+++ b/engine/api.py
@@ -58,7 +58,6 @@ class ClientCallbacks(Callbacks): #inherits from the templates api callbacks
         
         #self.playbackStart = []
         #self.playbackStop = []
-        self.playbackSpeedChanged = []
         self._cachedTickIndex = -1
 
         self.updateGraphTrackCC = []
@@ -68,9 +67,9 @@ class ClientCallbacks(Callbacks): #inherits from the templates api callbacks
         self.updateTempoTrack = []
         self.updateTempoTrackBlocks = []
         self.updateTempoTrackMeta = []
+        self.tempoScalingChanged = []
 
-        self.prevailingBaseDurationChanged = []        
-        self.metronomeChanged = []
+        self.prevailingBaseDurationChanged = []                
 
         #self.recordingStreamNoteOn = []
         #self.recordingStreamNoteOff = []
@@ -115,6 +114,8 @@ class ClientCallbacks(Callbacks): #inherits from the templates api callbacks
         changedTracks, currentItem = session.data.currentContentLinkAndItsBlocksInAllTracks()
         for track in changedTracks:
             self._updateTrack(id(track))
+            if session.data.currentMetronomeTrack is track:                               
+                setMetronome(track.asMetronomeData, label=track.name) #template api
 
     def  _updateTrack(self, trId):
         """The most important function. Create a static representation of the music data which
@@ -178,7 +179,8 @@ class ClientCallbacks(Callbacks): #inherits from the templates api callbacks
     def _tracksChanged(self):
         """Track deleted, added or moved. Or toggled double/non-double.
         This callback is relatively cheap because it does not generate
-        any item data."""                
+        any item data."""                        
+        #TODO: does NOT call template.api._numberOfTracksChanged
         session.data.updateJackMetadataSorting()
         
         if self.tracksChanged:
@@ -226,6 +228,10 @@ class ClientCallbacks(Callbacks): #inherits from the templates api callbacks
         #TODO: but this also leads to centerOn cursor in the gui after every mouse click in the conductor.
         #self._setCursor(destroySelection = False)
 
+    def _tempoScalingChanged(self, newValue):
+        for func in self.tempoScalingChanged:
+            func(newValue)
+
     def _playbackStart(self):
         for func in self.playbackStart:
             func()
@@ -234,9 +240,6 @@ class ClientCallbacks(Callbacks): #inherits from the templates api callbacks
         for func in self.playbackStop:
             func()
 
-    def _playbackSpeedChanged(self, newValue):
-        for func in self.playbackSpeedChanged:
-            func(newValue)
 
     def _prevailingBaseDurationChanged(self, newPrevailingBaseDuration):
         for func in self.prevailingBaseDurationChanged:
@@ -252,18 +255,6 @@ class ClientCallbacks(Callbacks): #inherits from the templates api callbacks
         for func in self.historyChanged:
             func(undoHistory, redoHistory)
 
-    def _metronomeChanged(self):
-        """returns a dictionary with meta data such as the mute-state and the track name"""
-        #Check if the actual track exists. This handles track delete of any kind.
-        #session.data.metronome.currentMetronomeTrack is not a calf box track but our Laborejo track that HOLDS the current cbox metronome track
-        return #TODO
-        if not session.data.metronome.currentMetronomeTrack or  not (session.data.metronome.currentMetronomeTrack in session.data.tracks or session.data.metronome.currentMetronomeTrack in session.data.hiddenTracks):
-            session.data.metronome.currentMetronomeTrack = None
-            session.data.metronome.useTrack(session.data.currentTrack())
-
-        for func in self.metronomeChanged:
-            func(session.data.metronome.staticRepresentation())
-
     def _recordingStreamNoteOn(self, liveChord):
         """One dict at a time"""
         trId = id(session.data.currentTrack())
@@ -290,7 +281,7 @@ def startEngine(nsmClient):
     _templateStartEngine(nsmClient)
     
     #Send initial Data etc.    
-    session.data.tempoMap.isTransportMaster = True #always true for Laborejo.
+    session.data.tempoMap.isTransportMaster = True #always true for Laborejo.    
     callbacks._tracksChanged()  # This creates the frontend/GUI tracks with access through track ids. From now on we can send the GUI a trId and it knows which track needs change.
     for trId in session.data.listOfTrackIds():
         callbacks._updateTrack(trId) #create content: music items
@@ -302,6 +293,8 @@ def startEngine(nsmClient):
     for track in session.data.hiddenTracks: #After loading a file some tracks could be hidden. We want midi for them as well.
         track.staticRepresentation()  #that generates the calfbox data as a side effect. discard the other data.
 
+    useCurrentTrackAsMetronome()    
+    
     callbacks._setCursor()       
     
     global laborejoEngineStarted #makes for a convenient check. stepMidiInput uses it, which needs to know that the gui already started the api.
@@ -414,21 +407,6 @@ def _updateCallbackAllTracks():
 
 updateCallbackAllTracks = _updateCallbackAllTracks
 
-def useCurrentTrackAsMetronome():
-    track = session.data.currentTrack()
-    session.data.metronome.useTrack(track)
-    callbacks._metronomeChanged() #updates playback as well
-
-def enableMetronome(value):
-    session.data.metronome.enabled = value #has side effects
-    callbacks._metronomeChanged() #updates playback as well
-
-def isMetronomeEnabled():
-    return session.data.metronome.enabled
-
-def toggleMetronome():
-    enableMetronome(not session.data.metronome.enabled) #handles callback etc.
-
 def _changeBlockAndItemOrder(dictWithTrackIDsAndDataLists):
     """A helper function for deleteSelection, paste and other...
     This makes it possible to undo/redo properly. It registers
@@ -472,10 +450,10 @@ def copyObjects(): #ctrl+c
     #The score doesn't change at all. No callback.
     #no undo.
 
-def pasteObjects(customBuffer = None, keepCursorState = False, overwriteSelection = True): #ctrl+v
+def pasteObjects(customBuffer = None, updateCursor = True, overwriteSelection = True): #ctrl+v
     """api.duplicate overrides default paste behaviour by providing its own copyBuffer
     and not destroying the selection/keep the cursor at its origin position
-    """
+    """    
     dataBefore = session.data.getBlockAndItemOrder()
     moveFunction = _createLambdaMoveToForCurrentPosition()
     listOfChangedTrackIDs = session.data.pasteObjects(customBuffer, overwriteSelection)
@@ -488,31 +466,31 @@ def pasteObjects(customBuffer = None, keepCursorState = False, overwriteSelectio
         #Make changes visible in the GUI
         for trackId in listOfChangedTrackIDs:
             callbacks._updateTrack(trackId)
-
-        if keepCursorState:
-            goTo()
-            callbacks._setCursor(destroySelection = False)
-        else:
+        
+        if updateCursor:
             callbacks._setCursor()
 
 def duplicate(): #ctrl+d
-    """Duplicate a single object and put it right of the original. Duplicate the entire selection
-    and put the copy right of the last selected note.
-    Basically a special case of copy and paste that does not touch the clipboard."""
+    """Duplicate a single object and put it right of the original. The cursor moves with it 
+    to enable follow up insertion.
+    
+    Duplicate the entire selection and put the copy right of the last selected note.
+    The cursor moves to selection start. deal with it.
+        
+    Basically a special case of copy and paste that does not touch the clipboard."""            
     if session.data.cursorWhenSelectionStarted:
-        #startPos = session.data.where() #we cannot use where() since we don't know if a content linked block before our current position gets new items in the duplication process
-        #TODO: when duplicating with content links or at least inside a content link the selection gets lost completely. Maybe this cannot be avoided, but review that in the future.
-
         customBuffer = session.data.copyObjects(writeInSessionBuffer = False)
-        if customBuffer:
-            session.data.goToSelectionStart()
-            pasteObjects(customBuffer = customBuffer, keepCursorState = True, overwriteSelection = False)
-    else:
+        if customBuffer: #success
+            session.data.goToSelectionStart()             
+            pos = session.data.where() #where even keeps the local position if a content linked block inserts items before our position                         
+            pasteObjects(customBuffer = customBuffer, updateCursor = False, overwriteSelection = False)            
+            session.data.goTo(*pos)
+            callbacks._setCursor(destroySelection=False)            
+    else:        
         item = session.data.currentItem()
         if item:
-            insertItem(item.copy())
-           
-            
+            insertItem(item.copy())                                
+        callbacks._setCursor()
 #Score
 def transposeScore(rootPitch, targetPitch):
     """Based on automatic transpose. The interval is caculated from two pitches.
@@ -521,6 +499,11 @@ def transposeScore(rootPitch, targetPitch):
     session.history.register(lambda r=rootPitch,t=targetPitch: transposeScore(t,r), descriptionString="transpose score")    
     _updateCallbackAllTracks()
 
+def useCurrentTrackAsMetronome():
+    """This is called once after loading/creating a session in startEngine"""
+    session.data.currentMetronomeTrack = session.data.currentTrack()        
+    setMetronome(session.data.currentMetronomeTrack.asMetronomeData, label=session.data.currentMetronomeTrack.name) #template api. has callbacks
+
 #Tracks
 def insertTrack(atIndex, trackObject):
     moveFunction = _createLambdaMoveToForCurrentPosition()
@@ -540,6 +523,7 @@ def newEmptyTrack():
     newTrack = Track(session.data)
     insertTrack(newIndex, newTrack) #handles callbacks and undo
     return (id(newTrack))
+    
 
 def deleteTrack(trId):
     """Can not delete hidden tracks because these don't implement undo.
@@ -2135,6 +2119,15 @@ def insertTempoChangeDuringDuration(percentageUnitsPerMinuteAsFloat):
         session.history.clear()  #TODO: This registers two times undo
 
 
+def currentTempoScalingFactor():
+    return session.data.tempoTrack.factor
+
+def changeTempoScaling(factor:float):
+    """The factor is always a factor from x1, not from the previous
+    value"""
+    session.data.tempoTrack.setFactor(float(factor))
+    callbacks._tempoScalingChanged(session.data.tempoTrack.factor)
+
 #Toolbox
 #High Level commands
 
diff --git a/engine/block.py b/engine/block.py
index 62a63d6..d2e5033 100644
--- a/engine/block.py
+++ b/engine/block.py
@@ -151,8 +151,9 @@ class Block(object):
         for item in self.data:
             copyItem = item.copy()
             new.data.append(copyItem)
-
-            copyItem.parentBlocks.add(new)  #parentBlock was empty until now
+            
+            assert not copyItem.parentBlocks #parentBlock was empty until now
+            copyItem.parentBlocks.add(new)  
             if self in copyItem.parentBlocks: #TODO: investigate
                 copyItem.parentBlocks.remove(self)
 
@@ -301,7 +302,7 @@ class Block(object):
     def insert(self, item):
         self.data.insert(self.localCursorIndex, item) #we do not need to check if appending or not. list.insert appends if the index is higher then len()
         #self.localCursorIndex += 1 #we don't need to go right here because track.insert() is calling its own right() directly after insert, which triggers block.right()
-        item.parentBlocks.add(self)
+        item.parentBlocks.add(self)        
 
     def delete(self):
         """The commented out is the immediate garbage collector which
diff --git a/engine/config.py b/engine/config.py
index ac9eba6..6715288 100644
--- a/engine/config.py
+++ b/engine/config.py
@@ -36,7 +36,7 @@ METADATA={
     
     #How many audio outputs do you want? must be pairs. These are just unconnected jack outputs 
     #that need to be connected internally to instrument outputs like fluidsynth
-    "cboxOutputs" : 2 * 0, 
+    "cboxOutputs" : 2 * 1,  #metronome
 
     #Various strings for the README
     #Extra whitespace will be stripped so we don't need to worry about docstring indentation
diff --git a/engine/graphtracks.py b/engine/graphtracks.py
index e906e42..71676b5 100644
--- a/engine/graphtracks.py
+++ b/engine/graphtracks.py
@@ -1313,6 +1313,13 @@ class TempoTrack(GraphTrackCC):
         assert self.blocks
 
 
+    @property
+    def factor(self):
+        return self.parentData.tempoMap.factor
+        
+    def setFactor(self, factor:float):
+        self.parentData.tempoMap.setFactor(factor)
+
     def lilypond(self):
         """Based on the static export"""
         def _ly(tempoItem, nextTempoItem):
diff --git a/engine/items.py b/engine/items.py
index c5601c1..3246a55 100644
--- a/engine/items.py
+++ b/engine/items.py
@@ -744,8 +744,13 @@ class Item(object):
 
 
     @property
-    def parentTracks(self):
-        return [block.parentTrack for block in self.parentBlocks]
+    def parentTracks(self):        
+        #return (block.parentTrack for block in self.parentBlocks[0])
+        return (block.parentTrack for block in list(self.parentBlocks)[0].linkedContentBlocksInScore())
+
+    @property
+    def parentTrackIds(self):
+        return (id(tr) for tr in self.parentTracks)
 
     def _copy(self):
         """return an independent copy of self"""
@@ -757,8 +762,8 @@ class Item(object):
         return new
 
     def copyParentBlocks(self, oldItem):
-        """Move the oldItems parentBlocks to the new item"""
-        self.parentBlocks = oldItem.parentBlocks
+        """Move the oldItems parentBlocks to the new item"""        
+        #self.parentBlocks = oldItem.parentBlocks #TODO. We took that out when pasting after deleting a track and recreating failed. Why do we to copy the parentBlocks when a parentBlock is added during block.insert anyway? Wild guess: we don't. 
 
     def logicalDuration(self):
         return 0
diff --git a/engine/main.py b/engine/main.py
index ffe0e0d..6042b14 100644
--- a/engine/main.py
+++ b/engine/main.py
@@ -23,12 +23,12 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 import logging; logging.info("import {}".format(__file__))
 
 #Standar Library
+import sys
 
 #3rd Party
 
 #Template
 import template.engine.sequencer
-from template.engine.metronome import Metronome
 
 #Our modules
 from .block import Block
@@ -56,11 +56,12 @@ class Data(template.engine.sequencer.Score):
         self.cursorWhenSelectionStarted = None #A cursor dict, from self.cursorExport(). Is None when there is no selection. Can be used for "if selection:" questions. Gets changed quite often.
         self.copyObjectsBuffer = [] #for copy and paste. obviously empty after load file. Also not saved.
         self.cachedTrackDurations = {} #updated after every track export
-        self.metronome = Metronome(parentData=self) #Purely dynamic structure. No save/load. No undo/redo       
+        self.currentMetronomeTrack = None #A Laborejo Track, indepedent of currentTrack. The metronome is in self.metronome, set by the template Score.        
 
     def duration(self):
         """Return the duration of the whole score, in ticks"""
-        #TODO: use cached duration? How often is this used?
+        #TODO: use cached duration? How often is this used?  Pretty often. 3 Times for a single track note update.
+        #TODO: Measure before trying to improve performance.        
         result = []
         for track in self.tracks:
             result.append(track.duration())
@@ -506,7 +507,7 @@ class Data(template.engine.sequencer.Score):
         result = []
         if validSelection:
             for track in selectedTracksAndItems:
-                result.append([item.copy() for item, cachedTrackState in track])
+                result.append([item.copy() for item, cachedTrackState in track])                
             if writeInSessionBuffer:
                 self.copyObjectsBuffer =  result
             return result
@@ -580,10 +581,11 @@ class Data(template.engine.sequencer.Score):
 
         if self.cursorWhenSelectionStarted and overwriteSelection:
             listOfChangedTrackIdsFromDelete = self.deleteSelection()
+            startPosition = self.where()
+            startItem = self.currentItem()
             #TODO: check if the cursor is still in the correct position after delete selection
 
         listOfChangedTrackIds = set()
-
         for number, track in enumerate(workBuffer):
             curTrack = self.currentTrack()
             #Here comes an additional condition. Most of the time pastes are single-track. If so, or we simply are in the starting track, we want to paste at the actual position, not the tickindex. This circumvents problems with block boundaries and zero-duration items.
@@ -597,8 +599,8 @@ class Data(template.engine.sequencer.Score):
             for item in track:
                 newItem = item.copy()
                 curTrack.insert(newItem) #eventhough copyObjectsBuffer is already a copy of the original notes we don't want every paste to be the same instances.
-                for parentBlock in newItem.parentBlocks: #TODO: just be naive and add them all for now. Performance can be improved later.
-                    listOfChangedTrackIds.add(id(parentBlock.parentTrack))
+                #newItem has now a parentBlock and a parentTrack. We add this parent track to the list of changed Tracks
+                listOfChangedTrackIds.update(newItem.parentTrackIds) #TODO: profiling. All items in a block have the same parentTrack. This is highly redundant BUT can be different for items which originated from block boundaries
             if not number+1 == len(workBuffer): #enumerate from 0, len from 1.
                 #we have to prevent the track going down one too far in the last step and messing with the tick index though.
                 self.trackDown()
@@ -609,10 +611,13 @@ class Data(template.engine.sequencer.Score):
             self.trackUp()
         assert self.trackIndex == trackIndexStart == startPosition[0]
         assert self.currentTrack().state.tickindex == finalTickIndex #this is not enough to pinpoint the real location.
-        self.goTo(trackIndex=startPosition[0], blockindex=startPosition[1], localCursorIndexInBlock=0)
+        
+        #Return to the item where pasting starting. Pasting counts as insert, and insert sticks to the item right of cursor.
+        #Therefore we go to the starting track and block, but not to the starting localCursorIndexInBlock. Instead we search for the specific item in a second step
+        self.goTo(trackIndex=startPosition[0], blockindex=startPosition[1], localCursorIndexInBlock=0)        
         self.goToItemInCurrentBlock(startItem) #we actually want to be at the same item where we started, not just the tick index which gets confused with block boundaries and zero duration items
 
-        try: #overwrite?
+        try: #overwrite? #TODO: What is that? assert with AssertionError pass?
             assert listOfChangedTrackIds == listOfChangedTrackIdsFromDelete
         except AssertionError:
             pass
@@ -811,12 +816,14 @@ class Data(template.engine.sequencer.Score):
             raise ValueError("graphItem with this id not in any track")
 
     def goTo(self, trackIndex, blockindex, localCursorIndexInBlock):
+        """Handles even shifting positions in a content link situation"""
         self.trackIndex = trackIndex
         self.currentTrack().toBlockAndLocalCursorIndex(blockindex, localCursorIndexInBlock)
         assert self.where() == (trackIndex, blockindex, localCursorIndexInBlock)
 
     def where(self):
-        """return the data needed by self.goto"""
+        """return the data needed by self.goto
+        where even keeps the local position if a content linked block inserts items before our position """
         return self.trackIndex, self.currentTrack().state.blockindex, self.currentTrack().currentBlock().localCursorIndex
 
     def goToItemInCurrentBlock(self, itemInstance):
diff --git a/engine/resources/metronome.sfz b/engine/resources/metronome.sfz
new file mode 100644
index 0000000..4a854a6
--- /dev/null
+++ b/engine/resources/metronome.sfz
@@ -0,0 +1,2 @@
+<region> key=77 sample=samples/normal.wav count=1     //normal metronome tick
+<region> key=76 sample=samples/stressed.wav count=1   //stressed metronome tick
diff --git a/engine/resources/normal.wav b/engine/resources/samples/normal.wav
similarity index 100%
rename from engine/resources/normal.wav
rename to engine/resources/samples/normal.wav
diff --git a/engine/resources/stressed.wav b/engine/resources/samples/stressed.wav
similarity index 100%
rename from engine/resources/stressed.wav
rename to engine/resources/samples/stressed.wav
diff --git a/engine/track.py b/engine/track.py
index 7bc62e6..cbb0e40 100644
--- a/engine/track.py
+++ b/engine/track.py
@@ -369,8 +369,8 @@ class TrackState(object):
 class Track(object):
     allTracks = WeakValueDictionary() #key is the trackId, value is the weak reference to the Track. Deleted tracks (from the current session) and hidden tracks are in here as well.
 
-    def __repr__(self) -> str:
-        return f"Laborejo Track: {self.sequencerInterface.name}"
+    #def __repr__(self) -> str:
+    #    return f"Laborejo Track: {self.sequencerInterface.name}"
 
     def __init__(self, parentData, name=None):
         self.parentData = parentData
@@ -395,6 +395,8 @@ class Track(object):
         #The instrument names are also handled by the trackState so that the cursor knows about instrument changes
         self.initialInstrumentName = "" #different than the track name. e.g. "Violin"
         self.initialShortInstrumentName = "" # e.g. "vl"
+                
+        self.asMetronomeData = None #This track as metronome version. Is always up to date through export.
         
         self._processAfterInit()
 
@@ -1060,10 +1062,10 @@ class Track(object):
         #########
 
         #Metronome start
-        #The metronome cannot be calculated by simply looking at metricalInstructions. We need to look at the barlines. Two instructions in a row at the same tick are wrong, but technically possible. These are not two full measures of metronome        
-        #TODO: metronome activate
-        #if self is self.parentData.currentMetronomeTrack:
-        #    self.parentData.metronome.generate(((pos, m.isMetrical, m.treeOfInstructions) for pos, m in barlines.items()))
+        #The metronome cannot be calculated by simply looking at metricalInstructions.
+        #We need to look at the barlines. Two instructions in a row at the same tick are wrong,
+        #but technically possible. These are not two full measures of metronome                
+        self.asMetronomeData = tuple((pos, m.isMetrical, m.treeOfInstructions) for pos, m in barlines.items())        
         #Metronome end. Nothing below is connected with the metronome subtrack.
 
         #Calculate the beam positions for the static groups.
@@ -1152,10 +1154,5 @@ class Track(object):
         self.toPosition(originalPosition, strict = False) #has head() in it
         return result
 
-
-
-
-
-
 #Dependency Injections.
 template.engine.sequencer.Score.TrackClass = Track #Score will look for Track in its module.
diff --git a/qtgui/menu.py b/qtgui/menu.py
index c380408..ba26262 100644
--- a/qtgui/menu.py
+++ b/qtgui/menu.py
@@ -539,10 +539,11 @@ class ToolBarMetronome(QtWidgets.QCheckBox):
             return False
 
     def updateFromCallback(self, exportDict):
+        """Gets the metronome dict"""        
         self.blockSignals(True)
         self.setStatus()
         assert self.isChecked() == exportDict["enabled"], (self.isChecked(), exportDict["enabled"])
-        self.setText("Metronome: " + exportDict["trackName"])
+        self.setText("Metronome: " + exportDict["label"])
         self.blockSignals(False)
 
     def changed(self, value):
@@ -554,10 +555,10 @@ class ToolBarPlaybackSpeed(QtWidgets.QDoubleSpinBox):
         super().__init__()
         self.setRange(0.1,3.0)
         self.setDecimals(1)
-        self.setValue(1.0)
+        self.setValue(api.currentTempoScalingFactor())
         self.setSingleStep(0.1)
         self.setPrefix("Tempo ×") #yes, this is the unicode multiplication sign × and not an x
-        api.callbacks.playbackSpeedChanged.append(self.updateFromCallback)
+        api.callbacks.tempoScalingChanged.append(self.updateFromCallback)
         self.valueChanged.connect(self.changed)
 
     def updateFromCallback(self, newValue):
@@ -566,5 +567,4 @@ class ToolBarPlaybackSpeed(QtWidgets.QDoubleSpinBox):
         self.blockSignals(False)
 
     def changed(self):
-        api.playbackChangeSpeed(self.value())
-        constantsAndConfigs.ccViewValue = self.value() #this sends a call back to all CC spinboxes in the whole program
+        api.changeTempoScaling(self.value())       
diff --git a/qtgui/scoreview.py b/qtgui/scoreview.py
index 1cc58e3..b2972c7 100644
--- a/qtgui/scoreview.py
+++ b/qtgui/scoreview.py
@@ -23,7 +23,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
 #Third Party
-from PyQt5 import QtCore, QtGui, QtWidgets
+from PyQt5 import QtCore, QtGui, QtWidgets, QtOpenGL
 #from PyQt5 import QtOpenGL
 
 #Template Modules
@@ -39,22 +39,21 @@ class ScoreView(QtWidgets.QGraphicsView):
     def __init__(self, mainWindow):
         super().__init__()
         self.mainWindow = mainWindow
-
-
-        #TODO: Measure OpenGL performance impact. Make sure fallback works
-        """
-        viewport = QtOpenGL.QGLWidget(QtOpenGL.QGLFormat(QtOpenGL.QGL.SampleBuffers))
-        viewport.format().setSwapInterval(0) #disable VSync.
-        viewport.setAutoFillBackground(False)
-
-        viewport = QtWidgets.QOpenGLWidget()
-        viewportFormat = QtGui.QSurfaceFormat()
-        viewportFormat.setSwapInterval(0) #disable VSync
-        viewportFormat.setSamples(2**8)
-        viewportFormat.setDefaultFormat(viewportFormat)
-        viewport.setFormat(viewportFormat)
-        self.setViewport(viewport)
-        """
+        
+        #OpenGL has a huge positive impact on performance
+        if True: #for testing
+            viewport = QtOpenGL.QGLWidget(QtOpenGL.QGLFormat(QtOpenGL.QGL.SampleBuffers))
+            viewport.format().setSwapInterval(0) #disable VSync.
+            viewport.setAutoFillBackground(False)
+
+            viewport = QtWidgets.QOpenGLWidget()
+            viewportFormat = QtGui.QSurfaceFormat()
+            viewportFormat.setSwapInterval(0) #disable VSync
+            #viewportFormat.setSamples(2**8) #By default, the highest number of samples available is used.
+            viewportFormat.setDefaultFormat(viewportFormat)
+            viewport.setFormat(viewportFormat)
+            self.setViewport(viewport)        
+        
 
         self.setAlignment(QtCore.Qt.AlignLeft|QtCore.Qt.AlignTop)
         #self.setDragMode(QtWidgets.QGraphicsView.RubberBandDrag)
diff --git a/qtgui/structures.py b/qtgui/structures.py
index 269f6b0..9a47bd7 100644
--- a/qtgui/structures.py
+++ b/qtgui/structures.py
@@ -22,7 +22,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 from math import log
 from PyQt5 import QtCore, QtGui, QtWidgets
 
-from .items import staticItem2Item, GuiTieCurveGraphicsItem, GuiLiveNote
+from .items import staticItem2Item, GuiTieCurveGraphicsItem
 from .constantsAndConfigs import constantsAndConfigs
 from .cursor import Cursor, Playhead, Selection
 from .conductor import Conductor, ConductorTransparentBlock
@@ -517,16 +517,6 @@ class GuiTrack(QtWidgets.QGraphicsItem):
                 backgroundColor.setOpacity(1)
             for tbh in self.transparentBlockHandles:
                 tbh.blockMode()
-    def recordingStreamNoteOn(self, liveNoteData):
-        guiLiveNote = GuiLiveNote(parent=self, liveNoteData=liveNoteData)
-        guiLiveNote.setX(liveNoteData["tickindex"] / constantsAndConfigs.ticksToPixelRatio)
-        self.parentScore.liveMidiWaitingForNoteOff[liveNoteData["midipitch"]] = guiLiveNote
-
-    def recordingStreamNoteOff(self, liveNoteData):
-        guiLiveNote = self.parentScore.liveMidiWaitingForNoteOff[liveNoteData["midipitch"]]
-        guiLiveNote.update(liveNoteData["duration"])
-        del self.parentScore.liveMidiWaitingForNoteOff[liveNoteData["midipitch"]]
-
 
 class GuiScore(QtWidgets.QGraphicsScene):
     def __init__(self, parentView):
@@ -541,8 +531,6 @@ class GuiScore(QtWidgets.QGraphicsScene):
         self._deleteOnIdleLoop.start(0) #0 means "if there is time"
         self._deleteOnIdleLoop.timeout.connect(self._deleteOnIdle) #processes deleteOnIdleStack
 
-        self.liveMidiWaitingForNoteOff = {} #all unfinished midi notes (key is currently held down). We use one for all tracks because we have a callback in the cursor update function that iterates over all live notes. We don't want that to iterate over all tracks just to find the current live notes.
-
         self.duringTrackDragAndDrop = None #switched to a QGraphicsItem (e.g. GuiTrack) while a track is moved around by the mouse
         self.duringBlockDragAndDrop = None #switched to a QGraphicsItem (e.g. GuiTrack) while a block is moved around by the mouse
 
@@ -584,11 +572,6 @@ class GuiScore(QtWidgets.QGraphicsScene):
         api.callbacks.updateGraphBlockTrack.append(self.updateGraphBlockTrack)
         api.callbacks.graphCCTracksChanged.append(self.syncCCsToBackend)
 
-        #api.callbacks.recordingStreamNoteOn.append(self.recordingStreamNoteOn)
-        #api.callbacks.recordingStreamNoteOff.append(self.recordingStreamNoteOff)
-        #api.callbacks.setPlaybackTicks.append(self._drawLiveMidiRecording)
-        #api.callbacks.recordingStreamClear.append(self.recordingStreamClear)
-
     def updateMode(self, nameAsString):
         assert nameAsString in constantsAndConfigs.availableEditModes
 
@@ -665,25 +648,7 @@ class GuiScore(QtWidgets.QGraphicsScene):
             self.removeWhenIdle(self.tracks[trackId].ccPaths[cc])
             del self.tracks[trackId].ccPaths[cc]
 
-    def recordingStreamNoteOn(self, trackId, liveChord):
-        if trackId in self.tracks:
-            self.tracks[trackId].recordingStreamNoteOn(liveChord)
-        #else:
-            #hidden track.
-        #self.parentView.updateMode()
-        #self.updateSceneRect()
-
-    def recordingStreamNoteOff(self, trackId, liveChord):
-        if trackId in self.tracks:
-            self.tracks[trackId].recordingStreamNoteOff(liveChord)
-        #else:
-            #hidden track.
-        #self.parentView.updateMode()
-        #self.updateSceneRect()
-
-    def recordingStreamClear(self):
-        removeInstancesFromScene(GuiLiveNote)
-
+ 
     def redraw(self, listOfStaticTrackRepresentations):
         """The order of guiTracks depends on the backend index.
         This way it is a no-brainer, we don't need to maintain our own
@@ -762,10 +727,6 @@ class GuiScore(QtWidgets.QGraphicsScene):
             self.removeItem(deleteMe) #This is the only line in the program that should call scene.removeItem
             del deleteMe
 
-    def _drawLiveMidiRecording(self, tickPosition):
-        for midiPitch, guiLiveNote in self.liveMidiWaitingForNoteOff.items():
-            guiLiveNote.update(tickPosition - guiLiveNote.liveNoteData["tickindex"])
-
 
     def trackAt(self, qScenePosition):
         """trackAt always returns the full GuiTrack, even if in ccEdit mode."""