Blue Oyster Cult - Vengeance (The Pact)

It wasn't until recently that I discovered that BOC's Fire of Unknown Origin album was supposed to be the soundtrack for the animated film Heavy Metal. For the life of me, I can't figure why the powers-that-be would scratch this and go with a soundtrack of various tunes from different bands. I'm sure the answer boils down to money. BOC's album is so perfect...in general and for the film.
Now I want to watch Heavy Metal!