class MidiReceiver implements Receiver {
  void close() {}
  
  void send( MidiMessage msg, long timeStamp ) { 
    // we only care about NoteOn midi messages.
    // here's how you check for that
    if ( msg instanceof ShortMessage ) {
      ShortMessage sm = (ShortMessage)msg;
      // if you want to handle messages other than NOTE_ON, you can refer to the constants defined in 
      // ShortMessage: http://docs.oracle.com/javase/6/docs/api/javax/sound/midi/ShortMessage.html
      // And figure out what Data1 and Data2 will be, refer to the midi spec: http://www.midi.org/techspecs/midimessages.php
      if ( sm.getCommand() == ShortMessage.NOTE_ON ) {
        // note number, between 1 and 127
        int note = sm.getData1();
        // velocity, between 1 and 127
        int vel  = sm.getData2();
        // we could also use sm.getChannel() to do something different depending on the channel of the message
        
        // see below the draw method for the definition of this sound generating Instrument
        
        System.out.println(note);
        out.playNote( 0, 0.1f, new Synth( note, vel ) ); 
      }
    }
  }
}