diff --git a/gtk2_ardour/midi_region_view.cc b/gtk2_ardour/midi_region_view.cc
index c74b91596a..249c198bfd 100644
--- a/gtk2_ardour/midi_region_view.cc
+++ b/gtk2_ardour/midi_region_view.cc
@@ -1101,8 +1101,6 @@ MidiRegionView::apply_diff (bool as_subcommand, bool was_copy)
 
 	if (commit) {
 		trackview.editor().commit_reversible_command ();
-		/* XXX the GUI should NOT be responsible for causing this call tree */
-		midi_view()->midi_track()->region_edited (_region);
 	}
 }
 
diff --git a/libs/ardour/ardour/disk_reader.h b/libs/ardour/ardour/disk_reader.h
index c9e4c0b6d4..80343a2029 100644
--- a/libs/ardour/ardour/disk_reader.h
+++ b/libs/ardour/ardour/disk_reader.h
@@ -128,7 +128,6 @@ protected:
 
 	void resolve_tracker (Evoral::EventSink<samplepos_t>& buffer, samplepos_t time);
 
-	void playlist_changed (const PBD::PropertyChange&);
 	int use_playlist (DataType, boost::shared_ptr<Playlist>);
 	void playlist_ranges_moved (std::list< Evoral::RangeMove<samplepos_t> > const &, bool);
 
diff --git a/libs/ardour/ardour/midi_region.h b/libs/ardour/ardour/midi_region.h
index 500c483827..6ae1375899 100644
--- a/libs/ardour/ardour/midi_region.h
+++ b/libs/ardour/ardour/midi_region.h
@@ -162,6 +162,7 @@ class LIBARDOUR_API MidiRegion : public Region
 	void update_length_beats (const int32_t sub_num);
 
 	void model_changed ();
+	void model_contents_changed ();
 	void model_shifted (double qn_distance);
 	void model_automation_state_changed (Evoral::Parameter const &);
 
@@ -171,6 +172,7 @@ class LIBARDOUR_API MidiRegion : public Region
 	std::set<Evoral::Parameter> _filtered_parameters; ///< parameters that we ask our source not to return when reading
 	PBD::ScopedConnection _model_connection;
 	PBD::ScopedConnection _model_shift_connection;
+	PBD::ScopedConnection _model_changed_connection;
 	PBD::ScopedConnection _source_connection;
 	PBD::ScopedConnection _model_contents_connection;
 	bool _ignore_shift;
diff --git a/libs/ardour/ardour/midi_track.h b/libs/ardour/ardour/midi_track.h
index ebe4e9bd56..556ab890ff 100644
--- a/libs/ardour/ardour/midi_track.h
+++ b/libs/ardour/ardour/midi_track.h
@@ -139,6 +139,8 @@ public:
 	void realtime_handle_transport_stopped ();
 	void region_edited (boost::shared_ptr<Region>);
 
+	int use_playlist (DataType, boost::shared_ptr<Playlist>);
+
 protected:
 
 	XMLNode& state (bool save_template);
@@ -174,6 +176,9 @@ private:
 	/** Update automation controls to reflect any changes in buffers. */
 	void update_controls (BufferSet const& bufs);
 	void restore_controls ();
+
+	void playlist_contents_changed ();
+	PBD::ScopedConnection playlist_content_change_connection;
 };
 
 } /* namespace ARDOUR*/
diff --git a/libs/ardour/disk_reader.cc b/libs/ardour/disk_reader.cc
index 6ee8b6585d..dcf783bcfc 100644
--- a/libs/ardour/disk_reader.cc
+++ b/libs/ardour/disk_reader.cc
@@ -204,12 +204,6 @@ DiskReader::adjust_buffering ()
 	}
 }
 
-void
-DiskReader::playlist_changed (const PropertyChange&)
-{
-	playlist_modified ();
-}
-
 void
 DiskReader::playlist_modified ()
 {
@@ -237,6 +231,8 @@ DiskReader::use_playlist (DataType dt, boost::shared_ptr<Playlist> playlist)
 	   take care of the buffer refill.
 	*/
 
+        cerr << "DR " << _track->name() << " using playlist, loading ? " << _session.loading() << endl;
+
         if (!overwrite_queued && (prior_playlist || _session.loading())) {
 		_session.request_overwrite_buffer (_track);
 		overwrite_queued = true;
@@ -258,7 +254,6 @@ DiskReader::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_samp
 	if (run_must_resolve) {
 		boost::shared_ptr<MidiTrack> mt = boost::dynamic_pointer_cast<MidiTrack> (_track);
 		if (mt) {
-			cerr << _track->name() << " resolving " << _tracker.on() << " notes @ " << start_sample << endl;
 			resolve_tracker (mt->immediate_events(), start_sample);
 		}
 		run_must_resolve = false;
@@ -532,8 +527,8 @@ DiskReader::overwrite_existing_buffers ()
 		midi_playlist()->render (0);
 		minsert.update();
 		assert (midi_playlist()->rendered());
-		//cerr << "Reading " << name()  << " took " << minsert.elapsed() << " microseconds, final size = " << midi_playlist()->rendered()->size() << endl;
-		//midi_playlist()->rendered()->dump (100);
+		// cerr << "Reading " << name()  << " took " << minsert.elapsed() << " microseconds, final size = " << midi_playlist()->rendered()->size() << endl;
+		// midi_playlist()->rendered()->dump (100);
 	}
 
 	g_atomic_int_set (&_pending_overwrite, 0);
diff --git a/libs/ardour/midi_playlist.cc b/libs/ardour/midi_playlist.cc
index a7092c45ba..00d1f5badd 100644
--- a/libs/ardour/midi_playlist.cc
+++ b/libs/ardour/midi_playlist.cc
@@ -416,7 +416,7 @@ MidiPlaylist::render (MidiChannelFilter* filter)
 
 	Playlist::RegionReadLock rl (this);
 
-	DEBUG_TRACE (DEBUG::MidiPlaylistIO, "---- MidiPlaylist::dump-----\n");
+	DEBUG_TRACE (DEBUG::MidiPlaylistIO, string_compose ("---- MidiPlaylist::render (regions: %1)-----\n", regions.size()));
 
 	std::vector< boost::shared_ptr<Region> > regs;
 
@@ -458,7 +458,7 @@ MidiPlaylist::render (MidiChannelFilter* filter)
 			continue;
 		}
 
-		DEBUG_TRACE (DEBUG::MidiPlaylistIO, string_compose ("dump from %1 at %2\n", mr->name()));
+		DEBUG_TRACE (DEBUG::MidiPlaylistIO, string_compose ("render from %1\n", mr->name()));
 		mr->render (*tgt, 0, _note_mode, filter);
 	}
 
diff --git a/libs/ardour/midi_region.cc b/libs/ardour/midi_region.cc
index d1a1f672d7..ee5d6e86df 100644
--- a/libs/ardour/midi_region.cc
+++ b/libs/ardour/midi_region.cc
@@ -541,7 +541,7 @@ MidiRegion::render (Evoral::EventSink<samplepos_t>& dst,
 		dst, // destination buffer
 		_position - _start, // start position of the source in session samples
 		_start + internal_offset, // where to start reading in the source
-		max_samplecnt,
+		_start + internal_offset + _length,
 		0,
 		cursor,
 		0,
@@ -670,7 +670,16 @@ MidiRegion::model_changed ()
 		);
 
 	model()->ContentsShifted.connect_same_thread (_model_shift_connection, boost::bind (&MidiRegion::model_shifted, this, _1));
+	model()->ContentsChanged.connect_same_thread (_model_changed_connection, boost::bind (&MidiRegion::model_contents_changed, this));
 }
+
+void
+MidiRegion::model_contents_changed ()
+{
+	std::cerr << "MIDI Region " << name() << " contents changed\n";
+	send_change (Properties::contents);
+}
+
 void
 MidiRegion::model_shifted (double qn_distance)
 {
@@ -685,6 +694,7 @@ MidiRegion::model_shifted (double qn_distance)
 		_start = new_start;
 		what_changed.add (Properties::start);
 		what_changed.add (Properties::start_beats);
+		what_changed.add (Properties::contents);
 		send_change (what_changed);
 	} else {
 		_ignore_shift = false;
diff --git a/libs/ardour/midi_track.cc b/libs/ardour/midi_track.cc
index 16d97a984c..53a3ed3366 100644
--- a/libs/ardour/midi_track.cc
+++ b/libs/ardour/midi_track.cc
@@ -873,9 +873,7 @@ MidiTrack::realtime_handle_transport_stopped ()
 }
 
 void
-MidiTrack::region_edited(boost::shared_ptr<Region> region)
+MidiTrack::playlist_contents_changed ()
 
 {
-	cerr << "MIDI region " << region->name() << " edited, queue reload\n";
-	_session.request_overwrite_buffer (boost::dynamic_pointer_cast<Track> (shared_from_this()));
 }
diff --git a/libs/ardour/playlist.cc b/libs/ardour/playlist.cc
index 417157f411..3cab0ef4aa 100644
--- a/libs/ardour/playlist.cc
+++ b/libs/ardour/playlist.cc
@@ -1772,14 +1772,18 @@ Playlist::region_changed (const PropertyChange& what_changed, boost::shared_ptr<
 	our_interests.add (Properties::muted);
 	our_interests.add (Properties::layer);
 	our_interests.add (Properties::opaque);
+	our_interests.add (Properties::contents);
 
 	bounds.add (Properties::start);
 	bounds.add (Properties::position);
 	bounds.add (Properties::length);
 
+	bool send_contents = false;
+
 	if (what_changed.contains (bounds)) {
 		region_bounds_changed (what_changed, region);
 		save = !(_splicing || _nudging);
+		send_contents = true;
 	}
 
 	if (what_changed.contains (Properties::position) && !what_changed.contains (Properties::length)) {
@@ -1788,8 +1792,6 @@ Playlist::region_changed (const PropertyChange& what_changed, boost::shared_ptr<
 		notify_region_end_trimmed (region);
 	} else if (what_changed.contains (Properties::position) && what_changed.contains (Properties::length)) {
 		notify_region_start_trimmed (region);
-	} else if (what_changed.contains (Properties::start)) {
-		notify_contents_changed ();
 	}
 
 	/* don't notify about layer changes, since we are the only object that can initiate
@@ -1800,6 +1802,10 @@ Playlist::region_changed (const PropertyChange& what_changed, boost::shared_ptr<
 		save = true;
 	}
 
+	if (send_contents || save) {
+		notify_contents_changed ();
+	}
+
 	mark_session_dirty ();
 
 	return save;