private void playSong(String song){
		// if no song has been started ie: beginning
		if(this.song == null){
			this.song = "tetrisb";
			clip = getAudioClip(getCodeBase(), this.song);
			clip.loop();
		}
		if(!this.song.equals(song)){
			clip.stop();
			clip = getAudioClip(getCodeBase(), song);				
			clip.loop();
			this.song = song;
		}
	}