1.通过触发onended事件调用函数改变音频的src(地址)来达到切歌

 <audio autoplay="autoplay" src="cfc.mp3" id="song" onended="change()"></audio> 
                                                      #onended DOM事件对象
 <script type="text/javascript">
    var song = document.getElementById('song');
    music =new Array('音乐存放的地址eg:media/xxx.mp3','xxxxxx','xxxx');
    function change() {
        if(song.ended){#判断音乐是否播放完
        index = Math.floor(Math.random()*music.length);
        #Math.floor()就近取整
        #Math.random() 0-1内的随机数 Math.random()*10代表0-10内的随机数
        song.src=music[index];
        song.play();
    }
 } 
</script>

2.通过设置监听事件

  <script type="text/javascript">
  var song = document.getElementById('song');
  music =new Array('media/cfc.mp3','media/fhm.mp3');
  song.addEventListener("onended" ,function(){
    if(song.ended){
    index = Math.floor(Math.random()*music.length);
    song.src=music[index];
    song.play();
  }
  });
  </script>

  照搬以上代码是运行不了的，把他放到window.onload=function(){   } 去,才能运行

  element.addEventListener(event, function, useCapture)