Create a button displaying Play / Pause.

<html>
<body>
<h4>Spotify</h4>
<p>Now playing: If You're Happy and You Know It</p>
<button>Previous</button>
<button>Play / Pause</button>
<button>Next</button>
</body>
</html>]]>

Make sure to pick <button>, followed by Play / Pause, and finally </button>.