If you just want the audio, you can hide the element that contains the video:
<div id="player" style="position: absolute; top: -9999px; left: -9999px;"></div>
Here we use absolute positioning with negative coordinates
display: none; will prevent the
from the Youtube player from triggering on Firefox. I ran across this problem
when making this.
Finally, here's a full example that will wait for the video to load and automatically play it: