A movie about a struggling band touring Canada, where one of the members manages to get herself vamped. Slowly, despite the protests of the guy ostensibly leading the band, it spreads to the rest of them- kind of metaphorical for drug-used, I suppose.

http://www.imdb.com/title/tt1323605/

It's nothing really new, but Malcom McDowell plays the Slayer, and the film both cracks me up, and makes me really sad for him.