Why Doesn't my midi player work

Question

//  MusicBox.java
//  sachs
//  Created by David Kopec on Mon Jul 14 2003.
//  Copyright (c) 2003 __MyCompanyName__. All rights reserved.
import javax.sound.midi.*;
import java.net.*;
import java.io.*;
import java.util.*;
public class MusicBox implements MetaEventListener, Runnable  {
    private String[] names;
    private boolean continuing;
    private Sequence sequence;
    private Sequencer sequencer;
    private Random r;
    public MusicBox(String[] ns, boolean c){
        names = ns;
        continuing = c;
        Random r = new Random();
        try{
            sequencer = MidiSystem.getSequencer();
            sequencer.open();
            sequencer.addMetaEventListener(this);
        catch (Exception e){
            e.printStackTrace();
        Thread t = new Thread(this);
    public void playRandom(){
        try{
            URL u;
            u = getClass().getResource(names[r.nextInt(names.length)]);
            sequence = MidiSystem.getSequence(u);
            sequencer.setSequence(sequence);
            sequencer.start();
        catch(Exception e){
            e.printStackTrace();
    public void run(){
        playRandom();
    //implement metaEventListener
    public void meta(MetaMessage event) {
        Thread t;
        if (event.getType() == 47) {
            // Sequencer is done playing
            if (continuing)
                t = new Thread(this);
    //clean up
    public void finalize() throws Throwable{
        sequencer.close();
        super.finalize();
}Any ideas? It's just silent.

Answer 1

Seems to me, you have not attached any receiver to the sequencer's transmitter. How a sequencer will generate a sound, it is required to be attaced to a Synthesizer. Try do something like following in your starting code:
try {
sequencer = MidiSystem.getSequencer();
sequencer.open();
sequencer.addMetaEventListener(this);
// similarly you have to obtain a synthesizer
synthesizer = MidiSystem.getSynthesizer();
synthesizer.open();
// now wire a synthesizer to a sequencer
sequencer.getTransmitter().setReceiver(synthesizer.getReceiver());
} catch (Exception e) {
e.printStackTrace();
Regards.