微信/易信内无法自动播放音乐解决办法：给音乐对象绑定WeixinJSBridgeReady / YixinJSBridgeReady事件即可。

function audioAutoPlay(id){  
   var audio = document.getElementById(id);  
    audio.play();  
    document.addEventListener("WeixinJSBridgeReady", function () {  
        audio.play();  
    }, false);  
    document.addEventListener('YixinJSBridgeReady', function() {  
        audio.play();  
    }, false);  
}  
audioAutoPlay('myMusic');