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();
  }
}

Began life as a copy of #1014503