MiniMusicPlayer3.java

package BeatBox;

import javax.sound.midi.*;
import javax.swing.*;
import java.awt.*;

public class MiniMusicPlayer3 {

	static JFrame f = new JFrame("My First Music Video");
	static MyDrawPanel ml;

	public static void main(String[] args) {
		MiniMusicPlayer3 mini = new MiniMusicPlayer3();
		mini.go();
	}

	public void setUpGui() {
		ml = new MyDrawPanel();
		f.setContentPane(ml);
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		f.setBounds(30, 30, 300, 300);
		f.setVisible(true);
	}

	public void go() {
		this.setUpGui();

		try {
			Sequencer sequencer = MidiSystem.getSequencer();
			sequencer.open();
			sequencer.addControllerEventListener(ml, new int[] { 127 });
			Sequence seq = new Sequence(Sequence.PPQ, 4);
			Track track = seq.createTrack();

			int r = 0;
			for (int i = 0; i < 61; i += 4) {
				r = (int) ((Math.random() * 50) + 1);
				track.add(makeEvent(144, 1, r, 100, i));
				track.add(makeEvent(176, 1, 127, 0, i));
				track.add(makeEvent(128, 1, r, 100, i + 2));
			}

			sequencer.setSequence(seq);
			sequencer.start();
			sequencer.setTempoInBPM(120);
		} catch (Exception ex) {
			ex.printStackTrace();
		}
	}

	public MidiEvent makeEvent(int comd, int chan, int one, int two, int tick) {
		MidiEvent event = null;
		try {
			ShortMessage a = new ShortMessage();
			a.setMessage(comd, chan, one, two);
			event = new MidiEvent(a, tick);
		} catch (Exception ex) {
		}
		return event;
	}

	class MyDrawPanel extends JPanel implements ControllerEventListener {
		boolean msg = false;

		@Override
		public void controlChange(ShortMessage event) {
			msg = true;
			this.repaint();
		}

		public void paintComponent(Graphics g) {
			if (msg) {
				Graphics2D g2 = (Graphics2D) g;

				int r = (int) (Math.random() * 250);
				int gr = (int) (Math.random() * 250);
				int b = (int) (Math.random() * 250);
				
				g2.setColor(new Color(r, gr, b));
				
				int ht = (int) ((Math.random() * 120) + 10);
				int width = (int) ((Math.random() * 120) + 10);
				int x = (int) ((Math.random() * 90) + 10);
				int y = (int) ((Math.random() * 90) + 10);
				
				g2.fillRect(x, y, ht, width);
				msg=false;
			}
		}
	}
}