As the lights dimmed before The Rocker, a kid behind me—trying to scare his sister—moaned, "The Reapah's heeah! THE REEEAPAAAH!" Good one, kid behind me. That joke was both funnier and more metal than the movie that was to come.

Robert "Fish" Fishman (Rainn Wilson, in his first leading role) is the drummer of and creative mastermind behind Vesuvius, an '80s hair band on the brink of its big break. For nonsense reasons I already forgot (something to do with selling out, I suppose), the band turns turncoat and kicks Fish to the curb. He spends the next 20 years bummed out and sloppy, while Vesuvius, um, (insert volcanic pun here). When his teenage nephew's band finds itself without a drummer, Fish unpacks his headband collection and his sweaty grimace and joins up.

The Rocker does not totally suck. Like most films devoted to the absurd kickassedness of rock, it's hopelessly derivative, but I've sat through worse moviegoing experiences than a secondhand Spinal Tap. (And, incidentally, were I forced to recast Spinal Tap for 2008, I'd probably head straight for Will Arnett, Fred Armisen, Bradley Cooper, and Lonny Ross—all fucking great as Vesuvius).

A band of cute teenagers on a steady rise to the top isn't exactly a recipe for dramatic tension—and apparently, it has been decreed that everyone in this movie shall be played by the aftertaste of Jack Black. But the bottomless charm factory that is Rainn Wilson (a man unafraid of looking like a human frog in a wig) mostly pulls it off. I do hope the Reaper doesn't come for his movie career quite yet.