1 import javax.sound.midi.*; 2 import javax.swing.*; 3 import java.awt.event.*; 4 import java.awt.*; 5  6 class MyPanel_2 extends JPanel implements ControllerEventListener{ 7     boolean msg = false; 8      9     public void paintComponent( Graphics g ) {10         if ( msg ) {11             g.fillRect(0, 0, this.getWidth(), this.getHeight());12             int red = (int) (Math.random() * 255);13             int green = (int) (Math.random() * 255);14             int blue = (int) (Math.random() * 255);15             Color randomColor = new Color(red, green, blue);16             g.setColor(randomColor);17             g.fillOval(70, 40, 100, 100);18             msg = false;19         }20     }21     22     public void controlChange(ShortMessage event) {23         msg = true;24         repaint();25     }26 }27 28 public class Midi{29     30     JFrame frame = new JFrame("My first Music Video");31     MyPanel_2 panel;    32     33     public void show_my_panel() {34         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);35         panel = new MyPanel_2();36         frame.setContentPane(panel);37         frame.setBounds(30, 30, 300, 300);38         frame.setVisible(true);39     }40     41     public static MidiEvent makeEvent(int cmd, int chan, int one, int two, int tick) {42         MidiEvent event = null;43         try {44             ShortMessage a = new ShortMessage();45             a.setMessage(cmd, chan, one, two);46             event = new MidiEvent(a, tick);47         } catch (Exception e) {}48         return event;49     }50     51     public void play() {52         try {53             Sequencer player = MidiSystem.getSequencer();54             player.open();55             56             int[] eventsIWant = {127};57             player.addControllerEventListener(panel, eventsIWant);58             59             Sequence seq = new Sequence(Sequence.PPQ, 4);//divisionType, resolution60             61             Track track = seq.createTrack();62             63             for (int i = 5; i < 61; i+= 4) {64                 track.add(makeEvent(144, 1, i, 100, i));65                 track.add(makeEvent(176, 1, 127, 0, i));66                 track.add(makeEvent(128, 1, i, 100, i + 2));67             }68             69             player.setSequence(seq);70             player.setTempoInBPM(220);71             player.start();72             while( player.isRunning() ) {                73                 Thread.sleep(1000);74             }75             player.close();76             77         } catch( Exception ex) {78             ex.printStackTrace();79         }80     }    81     82     public static void main(String[] args) {83         Midi midi = new Midi();84         85         midi.show_my_panel();86         midi.play();87     }88 }