here is the trick to trigger next song:

music.addEventListener('ended',function(){

      //play next song

    });

How to play another song on same audio tag:

 music.pause();

 music.src = new url;

 music.load();

 music.play();

Now here is a cool example of a playlist in html5, you can load each song at the time, case some clients (mobile) will not be happy when you consume the traffic, in next example all audios are loaded at same time to have a smooth transition from song to song,
loading the songs:

//playing flag 

var musicTracker = 'noMusic';

//playlist audios

var audios = [];

 $(.song).each(function(){

        var load = new  Audio($(this).attr(url));

    load.load();

    load.addEventListener('ended',function(){

       forward();

    });

    audios.push(load);

 });

//active track

var activeTrack = 0;

Highlighting witch song is playing, with a bit of jquery, yeah, case yeah I'm lazy, lazy:

var showPlaying = function()

{

    var src = audios[activeTrack].src;

   $(.song).removeClass(playing);

   $(div[url=' + src + ']).addClass(playing);

};

Fiddle here

Note: If the sound's doesn't play, manually check if audio url's are accessible