Incidentally, in his book Darwin's Dangerous Idea, Daniel C. Dennett suggests that the following would be, by its tune and character, an even more appropriate musical accompaniment for academic commencements, if not for the associations of its lyrics. It is, after all, titled "Behold the Lord High Executioner!"
I, of course, think that this ought to be used for all such occasions, but nobody ever asks me:
Congrats, grads! I hope the world's prospects improve for you, and soon.