private void controller_MessageReceived(object sender, MidiInMessageEventArgs e) { var noteOn = e.MidiEvent as NoteOnEvent; if (noteOn != null) { var track = GetTrack(noteOn.NoteNumber); if (track != null) { orchestrator.ActivateTrack(track); } switch (noteOn.NoteNumber) { case UP: break; case DOWN: break; case LEFT: break; case RIGHT: break; } } }