private void midiIn_MessageReceived(object sender, MidiInMessageEventArgs e) { if (e.MidiEvent is NoteOnEvent) { NoteOnEvent noteOn = (NoteOnEvent)e.MidiEvent; engine.addActiveMIDIKey(noteOn.NoteNumber); } else if (e.MidiEvent is NoteEvent) { NoteEvent noteOff = (NoteEvent)e.MidiEvent; engine.removeActiveMIDIKey(noteOff.NoteNumber); } }