diff --git a/libs/ardour/ardour/midi_scene_changer.h b/libs/ardour/ardour/midi_scene_changer.h
index c75e216ad3..e369048ea5 100644
--- a/libs/ardour/ardour/midi_scene_changer.h
+++ b/libs/ardour/ardour/midi_scene_changer.h
@@ -43,6 +43,10 @@ class MIDISceneChanger : public SceneChanger
 	void set_recording (bool);
 	void locate (framepos_t);
 
+        /** Signal emitted whenever any relevant MIDI activity is detected.
+         */
+        PBD::Signal0<void> MIDIActivity;
+
     private:
 	typedef std::multimap<framepos_t,boost::shared_ptr<MIDISceneChange> > Scenes;
 
diff --git a/libs/ardour/midi_scene_changer.cc b/libs/ardour/midi_scene_changer.cc
index e43f7de342..ba89e86096 100644
--- a/libs/ardour/midi_scene_changer.cc
+++ b/libs/ardour/midi_scene_changer.cc
@@ -254,6 +254,7 @@ MIDISceneChanger::bank_change_input (MIDI::Parser& parser, unsigned short, int)
 	}
 
 	last_bank_message_time = parser.get_timestamp ();
+        MIDIActivity (); /* EMIT SIGNAL */
 }
 
 void
@@ -304,6 +305,8 @@ MIDISceneChanger::program_change_input (MIDI::Parser& parser, MIDI::byte program
 	if (new_mark) {
 		locations->add (loc);
 	}
+
+        MIDIActivity (); /* EMIT SIGNAL */
 }
 
 void