Yes, you can embed YouTube videos, and then some, but not all can be shrunk down to 1x1px so they are not visible and set to autoplay so as to play in the background.
A word to the wise - Most background "music" is obnoxiously distracting from the story. I highly recommend never using autoplayed background music - as a bad connection can turn your masterfully selected 'piece' into a chopy 'piece of shit' in seconds.
Instead, I recommend making your music clickable by shrinking the videos down to 10 x 50 px as such:
<iframe width="10" height="50" src="http://www.youtube.com/embed/T6zDfxZ4NcE?feature=player_embedded" frameborder="0" allowfullscreen></iframe>