The journey from "School of Rock" to "School of Schlock" took just five years, which is nearly as long as some of the more interminable scenes in "The Rocker" seem to last.

In 2003's "School of Rock," a well-intentioned but slight comedy, Jack Black starred as a slobbish, wannabe rock star who uses his job as a fifth-grade substitute teacher to form a young band — the better to further his dreams of fame and guitar-shredding glory.

Now comes "The Rocker," a well-intentioned but even slighter comedy, in which Rainn Wilson stars as a slobbish-wannabe rock star who uses his lack of a job to join his teenage nephew's garage band — the better to revive his dreams of fame and drumstick-twirling glory.

Wilson, best known for his sidekick role as the bungling Dwight Schrute on TV's "The Office," is a reasonably competent comedian. But he spends so much of "The Rocker" winking, mugging and leering like a lobotomized Black on a bender that Wilson seems like the result of a Hollywood studio genetics experiment gone wrong.

Even if he had delivered an award-winning performance, it wouldn't have rescued "The Rocker." It isn't an awful movie, just a limp, dull, mundane one that squanders a very capable comedic cast on threadbare material and dimwitted clich?s. Full of stereotypical characters who are so broadly sketched that they almost evaporate at times, it's like a watered-down Judd Apatow comedy — Partial nudity! Age-inappropriate behavior! Recurring unpleasant bodily functions! — awkwardly mixed with a feel-good teen flick with a "serious" message about following your dreams and not compromising.

But just about everything in "The Rocker," with its composite of characters from better movies, feels compromised.

Wilson's character is named Robert "Fish" Fishman, an allusion to ex-Phish drummer Jon "Fish" Fishman that may be the most subtle touch in the entire film. Now in his 40s, Fish is still bitter 20 years after having been ousted from his band, a Poison-like Cleveland hair-metal quartet called Vesuvius, on the brink of its ascent to stardom.

Jobless, homeless and (surprise!) girlfriendless, Fish ends up joining A.D.D., a fledgling band that features his nephew Matt (Josh Gad, in a Jonah Hill-like role as a schlub with a heart of gold). After A.D.D. accidentally becomes a YouTube sensation, based on a band rehearsal video featuring Fish drumming in the nude, record companies come courting and a concert tour is mounted.

Most of the laughs that ensue are unintentional, although Gad gets in a good line about a pretty-boy drummer who briefly replaces Fish in A.D.D.: "It's like Abercrombie (& Fitch) is making people now."

After the band's first club gig, A.D.D. leader Curtis (nicely played by real-life teen singer-songwriter Teddy Geiger) is compared to Kurt Cobain, even though A.D.D.'s slick, Emo-lite songs are a lot closer to The Jonas Brothers than Nirvana.

Cleveland's Rock and Roll Hall of Fame is shown in so many scenes it almost deserves co-billing. But even the most minimal research would have corrected the notion that Vesuvius could be inducted into the Hall of Fame 20 (rather than 25) years after its debut recording.

Ex-Beatles drummer Pete Best, who is almost unrecognizable as himself, has a cameo at a bus-stop that's so brief you'll miss it if you blink. Too bad "The Rocker" isn't equally fleeting.

"The Rocker." Rated: PG-13. Running time: 1 hour, 42 minutes. 1 1/2 stars.

To find out more about George Varga and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.