please include function makeBasicMP3Player. // libs etc import javax.sound.sampled.LineUnavailableException; static void playMp3_javaSound_basicPlayer(File mp3, O... _) ctex { Number gain = cast optPar gain(_); fixContextClassLoader(); BasicPlayer player = new BasicPlayer { protected void initLine() throws LineUnavailableException { super.initLine(); if (gain != null) ctex { setGain(toDouble(gain)); } } }; player.open(mp3); player.play(); try { while (licensed() && player.getStatus() == player.PLAYING) sleep(10); } finally { player.stop(); } }