You can communicate between windows (tabbed or not) if they have a child-parent relationship.
Create and update a child window:
<html>
<head>
<title>Cross window test script</title>
<script>
var i = 0;
function open_and_run() {
var w2 = window.open("", "winCounter");
var myVar=setInterval(function(){myTimer(w2)},1000);
}
function myTimer(w2) {
i++;
w2.document.body.innerHTML="<center><h1>" + i + "</h1><p></center>";
}
</script>
</head>
<body>
Click to open a new window
<button onclick="open_and_run();">Test This!</button>
</body>
</html>
Child windows can use the parent object to communicate with the parent that spawned it, so you could control the music player from either window.
See it in action here: https://jsbin.com/cokipotajo/edit?html,js,output
