audioをplay, pauseするfunctionの中で、playしているli要素をboldにして、textContentで渡せばいいだけですね♪♪♪
<h2>Catcher In The Light<div style="display:inline;" id="title"></div></h2>
<p><audio src="/mp3/180307112410.mp3" preload="none" onclick="playthis(1);" controls="controls"></audio></p>
<ul>
<li id="list1"><a href="javascript:playthis(1)">Catcher In The Light</a></li>
<li id="list2"><a href="javascript:playthis(2)">About You</a></li>
<li id="list3"><a href="javascript:playthis(3)">GAME</a></li>
<li id="list4"><a href="javascript:playthis(4)">my name's WOMEN</a></li>
<li id="list5"><a href="javascript:playthis(5)">WONDERLAND</a></li>
</ul>
<script type="text/javascript">
var dir = "/foo/";
// var now = " ← now playing";
var media = document.getElementsByTagName("audio")[0];
var list = new Array(5);
list[1] = "hoge.mp3";
list[2] = "hogehoge.mp3";
list[3] = "hogehogehoge.mp3";
list[4] = "hogehogehogehoge.mp3";
list[5] = "hogehogehogehogehoge.mp3";
var length = list.length;
var COOKIE = new Array();
if (document.cookie) {
var cookies = document.cookie.split("; ");
for (var i = 0; i < cookies.length; i++) {
var str = cookies[i].split("=");
COOKIE[str[0]] = unescape(str[1]);
}
}
var volume = isNaN(COOKIE["volume"]) ? 0.5 : COOKIE["volume"];
media.volume = volume;
media.onended = function(){
playnext(this.src);
};
window.onbeforeunload = function(){ setCookie("volume", media.volume); };
</script>
<script type="text/javascript">
function playthis(key){
media.pause();
media.src = dir + list[key];
media.play();
var hoge =list[key];
var tag = document.getElementById("list"+key).innerHTML;
var title = tag.replace(/<("[^"]*"|'[^']*'|[^'">])*>/g,'');
var song = document.getElementById("title");
song.textContent = " : " + title;
// for(var i=1;i<length;i++) document.getElementById("list"+i).innerHTML = document.getElementById("list"+i).innerHTML.replace(now,"");
for(var i=1;i<length;i++) document.getElementById("list"+i).style.fontWeight = "normal";
document.getElementById("list"+key).style.fontWeight = "bold";
// document.getElementById("list"+key).innerHTML += now;
}
function playnext(objsrc) {
var objsrc = decodeURI(objsrc);
objsrc = objsrc.replace("http://"+location.host,"");
for (var i=1;i<length;i++) {
var listsrc = dir + list[i];
if(objsrc===listsrc){
if(length==i+1){
document.getElementById("list"+i).innerHTML = document.getElementById("list"+i).innerHTML.replace(now,"");
// 先頭を再生
// playthis(1);
}else{
playthis(i+1);
}
break;
}
}
}
function setCookie(name, value, domain, path, expires, secure) {
if (!name) return;
domain = location.hostname;
path = "/";
expires = 30;
var str = name + "=" + escape(value);
if (domain) {
if (domain == 1) domain = location.host.replace(/^[^\.]*/, "");
str += "; domain=" + domain;
}
if (path) {
if (path == 1) path = location.pathname;
str += "; path=" + path;
}
if (expires) {
var nowtime = new Date().getTime();
expires = new Date(nowtime + (60 * 60 * 24 * 1000 * expires));
expires = expires.toGMTString();
str += "; expires=" + expires;
}
if (secure && location.protocol == "https:") {
str += "; secure";
}
document.cookie = str;
}
</script>

