I was just thinking about this today actually. This is made by the guy who designed the Rockafire Explosion, not Chris Thrash. There's a whole sequence in the movie dedicated to its production. The guy who designed the band does all the voices and he got the girl who did the voice of Mitzi to come in to perform this. It's pretty amazing actually. I saw the movie a few months back in New York and I thought it was really good. Pretty sure the DVD is for sale on the website now