diff --git a/libs/ardour/ardour/midi_track.h b/libs/ardour/ardour/midi_track.h
index 8c908cdc9b..1cdeeda956 100644
--- a/libs/ardour/ardour/midi_track.h
+++ b/libs/ardour/ardour/midi_track.h
@@ -24,6 +24,7 @@
 
 #include "ardour/midi_channel_filter.h"
 #include "ardour/midi_ring_buffer.h"
+#include "ardour/key.h"
 #include "ardour/track.h"
 
 namespace ARDOUR
@@ -144,6 +145,12 @@ public:
 	void realtime_handle_transport_stopped ();
 	void region_edited (boost::shared_ptr<Region>);
 
+	MusicalKey const & key() const { return _key; }
+	void set_key (MusicalKey const & key);
+
+	bool enforce_key ();
+	void set_enforce_key (bool yn);
+
 protected:
 
 	XMLNode& state (bool save_template);
@@ -166,6 +173,9 @@ private:
 	MidiChannelFilter           _playback_filter;
 	MidiChannelFilter           _capture_filter;
 
+	MusicalKey                  _key;
+	bool                        _enforce_key;
+
 	void set_state_part_two ();
 	void set_state_part_three ();
 
diff --git a/libs/ardour/midi_track.cc b/libs/ardour/midi_track.cc
index 7ca6e9d796..38161c1b7e 100644
--- a/libs/ardour/midi_track.cc
+++ b/libs/ardour/midi_track.cc
@@ -87,6 +87,8 @@ MidiTrack::MidiTrack (Session& sess, string name, TrackMode mode)
 	, _step_editing (false)
 	, _input_active (true)
 	, _restore_pgm_on_load (true)
+	, _key (MusicalKey (MusicalMode::IonianMajor, 0))
+	, _enforce_key (false)
 {
 	_session.SessionLoaded.connect_same_thread (*this, boost::bind (&MidiTrack::restore_controls, this));