import javax.sound.midi.* ;
public class HelloChannel {
  public static void main(String[] args){
    MidiChannel channel = null;
    try {
      // Open Synthesizer
      Synthesizer synthesizer = MidiSystem.getSynthesizer();
      synthesizer.open();

      // load Instrument
      Soundbank soundbank = synthesizer.getDefaultSoundbank();
      Instrument[] instruments = synthesizer.getDefaultSoundbank().getInstruments();
      synthesizer.loadInstrument(instruments[0]);

      // Use first channel
      channel = synthesizer.getChannels()[0];
      System.out.println("Play pitch:48 velocity:128");
      channel.noteOn(48 , 64);
      Thread.currentThread().sleep(1000);
      channel.noteOff(128);
      System.out.println("Note off");
      synthesizer.close();
    } catch(Exception e){
      if(channel != null)  channel.allNotesOff();
    }
    System.exit(0);
  }
}