import java.io.File;
import java.io.IOException;

import javax.sound.midi.*
......
import processing.opengl.*;
import java.io.File;

private static Sequencer	sm_sequencer = null;
private static Synthesizer	sm_synthesizer = null;

void setup() {
  size(1200, 768, OPENGL);
  noLoop();
  frameRate(30);
  background(0);
}

void draw() 
{
  play();
}

void play()
{
  String	strFilename = "C:/Downloads/MIDI/bach/gold/goldberg.mid";
  File	midiFile = new File(strFilename);
  Sequence	sequence = null;
  sequence = MidiSystem.getSequence(midiFile);
  sm_sequencer = MidiSystem.getSequencer();

  sm_sequencer.addMetaEventListener(new MetaEventListener()
  {
    public void meta(MetaMessage event)
    {
      println("%%% MetaMessage: " + event);
      if (event.getType() == 47)
      { ...  }
    }
  }
  );

   sm_sequencer.open();
   sm_sequencer.setSequence(sequence);

  if (! (sm_sequencer instanceof Synthesizer))
  {
      sm_synthesizer = MidiSystem.getSynthesizer();
      sm_synthesizer.open();
      Receiver	synthReceiver = sm_synthesizer.getReceiver();
      Transmitter seqTransmitter = sm_sequencer.getTransmitter();
      seqTransmitter.setReceiver(synthReceiver);
  }
  sm_sequencer.start();
}

void keyPressed() {
  int PCKeyCode = keyCode;
  if (keyCode == 38) {
    sm_sequencer.setTempoFactor(sm_sequencer.getTempoFactor() - 0.1);
  } 
  else if(keyCode == 40) {
    sm_sequencer.setTempoFactor(sm_sequencer.getTempoFactor() + 0.1);
  }   
  println(keyCode + ":" + sm_sequencer.getTempoFactor());
}