点击光盘后音乐停止，可是光盘还是会变形

window.onload = function () {
    var music = document.getElementById("music");
    var audio = document.getElementsByTagName("audio")[0];

    audio.addEventListener("ended", function (event) {
        music.setAttribute("class", "");
    }, false);

    music.addEventListener("touchstart",function (event) {
        if (audio.paused) {
            audio.play();
            this.setAttribute("class"," music_play");
            //this.setAttribute("class","music_play");   //停止时变形
            // this.style.animationPlayState="running";   兼容性不行
        }
        else {
            audio.pause();
            this.setAttribute("class","");
            //this.style.animationPlayState="paused";
        }
    },false);
};

CSS部分：

.music > img.music_disc {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    width: 79%;
    margin: auto;
    z-index: 0;
}

.music > img.music_play {
    -webkit-animation: music_disc 4s linear infinite;
    -o-animation: music_disc 4s linear infinite;
    animation: music_disc 4s linear infinite;
}