Wilson has taken his lumps for The Rocker, in which he plays Robert “Fish” Fishman, a has-been drummer who catches on with his nephew’s band for one last shot at glory. It’s true that the character acts and sounds very much like Jack Black’s nutty music professor in the far superior School of Rock, as several critics have dismissively noted. But give Wilson credit for throwing himself into the part with abandon, frequently launching himself into his drum kit and off the stage without regard for his personal safety.

Too bad he couldn’t have sacrificed himself in the name of a better movie. Not that there’s anything terribly offensive about The Rocker – it’s a harmless, forgettable diversion, with a soundtrack as blandly generic as much of its biteless humor. But there is potential here, needlessly squandered by a story that takes no creative chances.

Fish, unceremoniously dumped by his soon-to-be-famous bandmates back in the ’80s, is an overgrown child consumed by bitterness and unwilling to trim his rock-’n’-roll mane after two decades on the sidelines. He’s irresponsible, inappropriate and hopelessly out of touch – ripe with comic possibility, in other words – but Maya Forbes and Wally Wolodarsky’s screenplay merely requires him to wander about in various states of undress and fall down a lot.

Does Fish feel like a character written for Jack Black or even Will Ferrell, whose pale paunch would seem right at home in The Rocker? Yes, but that hardly detracts from Wilson’s amiably wild-eyed performance, which hits all the scripted notes in a comedy that is mostly tone-deaf.