...

The main reason I think Joss Whedon decided to use music in this episode is because for the most part society accepts music as a way to express oneself without having repercussions. However, not only did Joss make it so that characters had a means through which to tell their secrets, he made it impossible for them to stop themselves. I personally think that Buffy needed a damn good reason to tell her friends what had happened, and Joss didn't have one... so he made a demon that would force her to.

Obviously there are consequences when "life is but a song," but seriously, I think it was high time Buffy told her friends what was up. And I was also extremely sick of Willow taking advantage of Tara... so thank God for tap dancing interpretations of Satan.

Also... just to throw this out there... I LOVED all the references to other musicals. For example "The Music Man" when Spike says "76 bloody trombones" and someone said "the Point of no return," which is from "the Phantom of the Opera." I'm also pretty sure that that street-sweeper dance routine was from some movie or musical along the way. How entertaining.