diff --git a/libs/ardour/ardour/midi_track.h b/libs/ardour/ardour/midi_track.h
index 0bf54bf469..be3625b61a 100644
--- a/libs/ardour/ardour/midi_track.h
+++ b/libs/ardour/ardour/midi_track.h
@@ -30,6 +30,11 @@
 namespace ARDOUR
 {
 
+namespace Properties {
+	LIBARDOUR_API extern PBD::PropertyDescriptor<MusicalKey::Type> musical_mode;
+	LIBARDOUR_API extern PBD::PropertyDescriptor<int> musical_root;
+}
+
 class InterThreadInfo;
 class MidiPlaylist;
 class RouteGroup;
@@ -44,6 +49,8 @@ public:
 
 	int init ();
 
+	static void make_property_quarks ();
+
 	void realtime_locate (bool);
 	void non_realtime_locate (samplepos_t);
 
diff --git a/libs/ardour/globals.cc b/libs/ardour/globals.cc
index 54252c2b39..0e4a9271d4 100644
--- a/libs/ardour/globals.cc
+++ b/libs/ardour/globals.cc
@@ -108,6 +108,7 @@
 #include "ardour/filesystem_paths.h"
 #include "ardour/midi_patch_manager.h"
 #include "ardour/midi_region.h"
+#include "ardour/midi_track.h"
 #include "ardour/midi_ui.h"
 #include "ardour/midiport_manager.h"
 #include "ardour/mix.h"
@@ -563,6 +564,7 @@ ARDOUR::init (bool try_optimization, const char* localedir, bool with_gui)
 	PresentationInfo::make_property_quarks ();
 	TransportMaster::make_property_quarks ();
 	Trigger::make_property_quarks ();
+	MidiTrack::make_property_quarks ();
 
 	/* this is a useful ready to use PropertyChange that many
 	   things need to check. This avoids having to compose
diff --git a/libs/ardour/midi_track.cc b/libs/ardour/midi_track.cc
index d50fa99460..3d7d24d734 100644
--- a/libs/ardour/midi_track.cc
+++ b/libs/ardour/midi_track.cc
@@ -72,12 +72,27 @@ class InterThreadInfo;
 class MidiSource;
 class Region;
 class SMFSource;
+
+
+namespace Properties {
+	PBD::PropertyDescriptor<MusicalMode::Type> musical_mode;
+	PBD::PropertyDescriptor<int> musical_root;
+}
 }
 
 using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 
+void
+MidiTrack::make_property_quarks ()
+{
+	Properties::musical_mode.property_id = g_quark_from_static_string (X_("musical-mode"));
+	DEBUG_TRACE (DEBUG::Properties, string_compose ("quark for musical-mode = %1\n", Properties::musical_mode.property_id));
+	Properties::musical_root.property_id = g_quark_from_static_string (X_("musical-root"));
+	DEBUG_TRACE (DEBUG::Properties, string_compose ("quark for musical-root = %1\n", Properties::musical_root.property_id));
+}
+
 MidiTrack::MidiTrack (Session& sess, string name, TrackMode mode)
 	: Track (sess, name, PresentationInfo::MidiTrack, mode, DataType::MIDI)
 	, _immediate_events(6096) // FIXME: size?
@@ -138,6 +153,13 @@ void
 MidiTrack::set_key (MusicalKey const & k)
 {
 	_key = k;
+
+	PropertyChange pc;
+
+	pc.add (Properties::musical_mode);
+	pc.add (Properties::musical_root);
+
+	PropertyChanged (pc); /* EMIT SIGNAL */
 }
 
 void