Web Audio APIでmp3を再生するだけ - Qiita

var context = new AudioContext(); var buffer = null; var source = context.createBufferSource(); var request = new XMLHttpRequest(); request.open('GET', 'xxx.mp3', true); request.responseType = 'arraybuffer'; request.send(); request.onload = function () { var res = request.response; context.decodeAudioData(res, function (buf) { source.buffer = buf; }); }; source.connect(context.destination); source