jestemtrying to paint JFrame when music is played , kształty te są tworzone losowo bez obliczeń i gdy istniejesome music played there pops up a JFrame and these shapes are painted there, Problem polega na tym, że kiedy uruchamiam ten kod, nie ma narysowanego dźwięku muzycznego i kształtów, ale po prostu pojawia się ramka i nic więcej, Plase sprawdź ten kod i pomóż mi go poprawić ..

public class MusicBeatsDrawing {

    static JFrame frame; 
    DrawPanel dp =new DrawPanel();
    public static void main(String[] args)
    {
        MusicBeatsDrawing mbd= new MusicBeatsDrawing();
        mbd.go();

    }
    public void SetGui(){

        frame= new JFrame("Simple frame ; ");
        frame.setBounds(100, 100, 200, 200); 
        frame.setContentPane(dp);
        frame.setVisible(true);

    }

    public void go()
    {
        SetGui();
        try
        {
            Sequencer sequencer =  MidiSystem.getSequencer();
            sequencer.open(); 

            Sequence seq= new Sequence(Sequence.PPQ, 4);
            sequencer.addControllerEventListener(dp,new int [] {127});
            Track track =  seq.createTrack(); 
            int r  =  0; 
            for  (int  i  =  0; i  <  60 ; i+=  4) {

                r =  (int) Math.random()*50; 
                track.add(MakeEvent(144,1,r,100,i)); 
                track.add(MakeEvent(176,1,127,0,i)); 
                track.add(MakeEvent(128,1,r,100,i ));
            }
            sequencer.setSequence(seq);
            sequencer.start();
        }

        catch(Exception e)
        {e.printStackTrace(); }
    }

    public  MidiEvent  MakeEvent(int one , int two , int three , int four , int tick)
    {   
        MidiEvent event= null;
        try 
        {    
            ShortMessage sm= new ShortMessage();
            sm.setMessage(one,two, three, four);
            event= new MidiEvent(sm , tick );


        } catch (InvalidMidiDataException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return  event;   
    }
    class DrawPanel extends  JPanel implements ControllerEventListener
    {       
        boolean msg= false ; 


        public void paintComponent(Graphics g)
        {
            if(msg){ Graphics2D g2d= (Graphics2D) g; 

            int red= (int) (Math.random()*255); 
            int green= (int) (Math.random()*255) ;
            int blue= (int) (Math.random()*255); 

            g.setColor(new Color(red, green , blue));

            int height= (int)Math.random()*255;
            int width= (int)Math.random()*255;
            int x= (int)Math.random()*255;
            int y= (int)Math.random()*255;
            g.fillRect(height, width, x, y);        
            msg = false; 
            }
        }
        @Override
        public void controlChange(ShortMessage event) {
            msg= true; 
            repaint();          
        }}


}