HTML5 MP3 player play the song list automatically?
Please check below javascript file link to auto play playlist
http://html5.svnlabs.com/audiojs/audio.js
settings: {
autoplay: true,
You need to update audio.js file in “wp-content/plugins/html5-mp3-player-with-playlist/html5/audiojs/”
OR
Add below statement in player file html5small.php, html5full.php or html5big.php on body load function 
$(‘.playing’).click(); //for autoplay
