diff --git a/include/instrument.h b/include/instrument.h
index 122fcbc22..a1be74c6f 100644
--- a/include/instrument.h
+++ b/include/instrument.h
@@ -85,12 +85,6 @@ public:
 		return( 0 );
 	}
 
-	// TO BE REMOVED
-	virtual bool isMonophonic( void ) const
-	{
-		return( FALSE );
-	}
-
 	// instrument-play-handle-based instruments should return FALSE
 	inline virtual bool notePlayHandleBased( void ) const
 	{
diff --git a/include/instrument_track.h b/include/instrument_track.h
index 8bee54fdd..2995eb75f 100644
--- a/include/instrument_track.h
+++ b/include/instrument_track.h
@@ -70,8 +70,7 @@ public:
 							notePlayHandle * _n );
 
 	virtual void processInEvent( const midiEvent & _me,
-					const midiTime & _time,
-							bool _lock = TRUE );
+					const midiTime & _time );
 	virtual void processOutEvent( const midiEvent & _me,
 						const midiTime & _time );
 
diff --git a/include/midi_controller.h b/include/midi_controller.h
index 3da728fc9..d6e52f4f4 100644
--- a/include/midi_controller.h
+++ b/include/midi_controller.h
@@ -51,8 +51,7 @@ public:
 
 
 	virtual void processInEvent( const midiEvent & _me,
-					const midiTime & _time,
-					bool _lock = TRUE );
+					const midiTime & _time );
 
 	virtual void processOutEvent( const midiEvent& _me,
 					const midiTime & _time)
diff --git a/include/midi_event_processor.h b/include/midi_event_processor.h
index ff9dfdd08..bd3b1646f 100644
--- a/include/midi_event_processor.h
+++ b/include/midi_event_processor.h
@@ -44,8 +44,7 @@ public:
 
 	// to be implemented by inheriting classes
 	virtual void processInEvent( const midiEvent & _me,
-						const midiTime & _time,
-							bool _lock = TRUE ) = 0;
+						const midiTime & _time ) = 0;
 	virtual void processOutEvent( const midiEvent & _me,
 						const midiTime & _time ) = 0;
 
diff --git a/include/midi_port.h b/include/midi_port.h
index 46d78d29a..d01dab6eb 100644
--- a/include/midi_port.h
+++ b/include/midi_port.h
@@ -111,9 +111,9 @@ public:
 	}
 
 	void subscribeReadablePort( const QString & _port,
-							bool _subscribe = TRUE );
+						bool _subscribe = TRUE );
 	void subscribeWriteablePort( const QString & _port,
-							bool _subscribe = TRUE );
+						bool _subscribe = TRUE );
 
 	const map & readablePorts( void ) const
 	{
diff --git a/src/core/midi/midi_controller.cpp b/src/core/midi/midi_controller.cpp
index 2196abb40..376844155 100644
--- a/src/core/midi/midi_controller.cpp
+++ b/src/core/midi/midi_controller.cpp
@@ -79,7 +79,7 @@ void midiController::updateName( void )
 
 
 void midiController::processInEvent( const midiEvent & _me,
-					const midiTime & _time, bool _lock )
+						const midiTime & _time )
 {
 	Uint8 controllerNum;
 	const Uint8 * bytes;
diff --git a/src/core/note_play_handle.cpp b/src/core/note_play_handle.cpp
index 1f023f896..6ad9516ff 100644
--- a/src/core/note_play_handle.cpp
+++ b/src/core/note_play_handle.cpp
@@ -260,10 +260,6 @@ void notePlayHandle::play( bool _try_parallelizing,
 
 f_cnt_t notePlayHandle::framesLeft( void ) const
 {
-/*	const instrument * i = ( m_instrumentTrack != NULL ) ?
-				m_instrumentTrack->getInstrument() : NULL;
-	f_cnt_t rftd  = ( i != NULL && i->isMonophonic() ) ?
-						0 : actualReleaseFramesToDo();*/
 	if( m_released && actualReleaseFramesToDo() == 0 )
 	{
 		return( m_framesBeforeRelease );
diff --git a/src/tracks/instrument_track.cpp b/src/tracks/instrument_track.cpp
index a217b9495..e1d4d5e42 100644
--- a/src/tracks/instrument_track.cpp
+++ b/src/tracks/instrument_track.cpp
@@ -207,7 +207,7 @@ void instrumentTrack::processAudioBuffer( sampleFrame * _buf,
 
 
 void instrumentTrack::processInEvent( const midiEvent & _me,
-					const midiTime & _time, bool _lock )
+							const midiTime & _time )
 {
 	switch( _me.m_type )
 	{
@@ -246,10 +246,6 @@ void instrumentTrack::processInEvent( const midiEvent & _me,
 
 		case MidiNoteOff:
 		{
-			if( _lock )	// TO BE REMOVED
-			{
-			engine::getMixer()->lock();
-			}
 			notePlayHandle * n = m_notes[_me.key()];
 			if( n != NULL )
 			{
@@ -270,10 +266,6 @@ void instrumentTrack::processInEvent( const midiEvent & _me,
 
 				emit noteDone( done_note );
 			}
-			if( _lock )	// TO BE REMOVED
-			{
-				engine::getMixer()->unlock();
-			}
 			break;
 		}
 
@@ -360,60 +352,6 @@ void instrumentTrack::playNote( notePlayHandle * _n, bool _try_parallelizing,
 
 	if( _n->arpBaseNote() == FALSE && m_instrument != NULL )
 	{
-		// TO BE REMOVED
-		if( m_instrument->isMonophonic() )
-		{
-			constNotePlayHandleVector v =
-				notePlayHandle::nphsOfInstrumentTrack( this,
-									TRUE );
-			if( v.size() > 1 )
-			{
-				constNotePlayHandleVector::iterator
-						youngest_note = v.begin();
-				for( constNotePlayHandleVector::iterator it =
-						v.begin(); it != v.end(); ++it )
-				{
-					if( !( *it )->arpBaseNote() &&
-						( *it )->totalFramesPlayed() <=
-						( *youngest_note )->
-							totalFramesPlayed() )
-					{
-						youngest_note = it;
-					}
-				}
-				if( *youngest_note != _n &&
-					!( *youngest_note )->arpBaseNote() &&
-					!_n->released() )
-				{
-					processInEvent(midiEvent(
-								MidiNoteOff, 0,
-						_n->key(), 0 ), midiTime(),
-									FALSE );
-					if( ( *youngest_note )->offset() >
-								_n->offset() )
-					{
-						_n->noteOff( ( *youngest_note )->
-								offset() -
-								_n->offset() );
-					}
-					else
-					{
-						// for the case the youngest
-						// note has an offset smaller
-						// then the current note we
-						// already played everything
-						// in last period and have
-						// to clear parts of it
-						_n->noteOff();
-	engine::getMixer()->clearAudioBuffer( m_audioPort.firstBuffer(),
-				engine::getMixer()->framesPerPeriod() -
-					( *youngest_note )->offset(),
-					( *youngest_note )->offset() );
-						return;
-					}
-				}
-			}
-		}
 		// all is done, so now lets play the note!
 		m_instrument->playNote( _n, _try_parallelizing,
 							_working_buffer );