Criando sequência de sons MIDI

package exemplo.midi;

import javax.sound.midi.InvalidMidiDataException;
import javax.sound.midi.MidiEvent;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.MidiUnavailableException;
import javax.sound.midi.Sequence;
import javax.sound.midi.Sequencer;
import javax.sound.midi.ShortMessage;
import javax.sound.midi.Track;

public class Midi {

    /**
     * @param args
     * @throws InvalidMidiDataException
     * @throws MidiUnavailableException
     * @throws InterruptedException
     */
    public static void main(String[] args) throws InvalidMidiDataException, MidiUnavailableException, InterruptedException {

        Sequencer player = MidiSystem.getSequencer();
        player.open();
        Sequence seq = new Sequence(Sequence.PPQ, 4);
        Track track = seq.createTrack();

        ShortMessage a = new ShortMessage();
        a.setMessage(144, 1, 44, 100);              // 144 significa reproduzir a nota 44
        MidiEvent noteOn = new MidiEvent(a, 1);     // Nota inicia no momento 1
        track.add(noteOn);

        ShortMessage b = new ShortMessage();
        b.setMessage(128, 1, 44, 100);              // 128 significa parar a nota 44
        MidiEvent noteOff = new MidiEvent(b, 12);   // Nota para no momento 12
        track.add(noteOff);

        ShortMessage c = new ShortMessage();
        c.setMessage(144, 1, 59, 100);              // 144 significa reproduzir a nota 59
        noteOn = new MidiEvent(c, 9);               // Nota inicia no momento 9
        track.add(noteOn);

        ShortMessage d = new ShortMessage();
        d.setMessage(128, 1, 59, 100);              // 128 significa parar a nota 59
        noteOff = new MidiEvent(d, 16);             // Nota para no momento 16
        track.add(noteOff);

        player.setSequence(seq);

        player.start();
        Thread.sleep(1000 * 2);
        player.close();
        System.exit(0);
    }

}