Get Him to the Greek

One of several scene-stealers in 2008’s “Forgetting Sarah Marshall” was Aldous Snow, the hedonistic, hard-partying rock star played by Russell Brand. It was the British comic’s first major exposure in the U.S., and it led to a regimen of MTV gigs and funny talk-show appearances, all of which seemed to reinforce the idea that Aldous Snow and Russell Brand are not very different from one another.

Now comes an Aldous Snow spinoff, called “Get Him to the Greek,” in which a hapless record-label employee must escort the libidinous, drug-addled rocker to L.A. in time for a comeback concert. The premise is ripe with potential, especially in the hands of uber-producer Judd Apatow and writer/director Nicholas Stoller (who directed “Forgetting Sarah Marshall), who have already demonstrated how far a comedic premise can be taken when you aren’t afraid of an R rating. Centering a movie on a character originally meant to be a one-dimensional sideliner is risky, and Aldous Snow doesn’t quite withstand the scrutiny. But Brand inhabits him so completely, so enthusiastically, that it’s hard not to be impressed by his commitment to the joke.

As the film opens, Aldous has fallen on hard times, his condescending “message” album “African Child” having been dubbed the third-worst thing to happen to Africa, after war and famine. He has split from his long-time partner Jackie Q (Rose Byrne), whose pop career continues to spiral upward. He has also gone off the wagon — spectacularly, in fact, devouring more booze and drugs than most mortals can survive.

His label, Pinnacle Records, schedules a gig at L.A.’s Greek Theatre, where 10 years ago he recorded a live album that went platinum. Assigned to get Aldous from London to the show is Aaron Green (Jonah Hill), an eager mid-level executive who genuinely loves Aldous’ work (except for “African Child,” which everyone hated). His boss, Pinnacle honcho Sergio Roma (Sean Combs), has dealt with petulant, irresponsible rock stars before, and warns Aaron that babysitting Aldous for 72 hours will not be easy. This is an understatement.

About an hour of solid, raucous comedy ensues, brutally mocking the fakeness of the modern music industry while treating us to an enjoyable series of Russell Brand/Jonah Hill sketches. Aaron drinks Aldous’ liquor and smokes his pot to keep it away from Aldous. Aldous makes unreasonable demands that must be met because he is the Talent and accustomed to getting whatever he wants. Aaron is required to procure heroin for Aldous. Aldous makes Aaron have sex with a stripper. You know, stuff like that.

But the film’s third act takes a weird turn. Aaron has been having problems with his girlfriend, Daphne (Elisabeth Moss), and somehow his three-day ordeal with Aldous is supposed to have taught him something. But Aaron is kind of a nothing character, and his relationship troubles aren’t interesting. Aldous, meanwhile, is an interesting character, but the movie starts to take his substance-abuse problems seriously — which is a real downer, comedy-wise. We’ve been laughing at his outrageously self-destructive behavior, and now suddenly it’s no laughing matter? Not fair.

Aldous is a fun train wreck to watch, though, thanks to Brand’s mischievous and mesmerizing screen presence. (Jonah Hill, while competent, doesn’t leave much of an impression.) Also surprisingly useful is Sean Combs as the foul-mouthed music-industry insider. Combs must have a lot of personal experience with this sort of thing, but he never lets the character become a winking self-reference, which could easily have been a temptation in a movie laced with celebrities-playing-themselves cameos. (Since when does Lars Ulrich have a sense of humor?)

As has often been the case with the Apatow-produced comedies, this one doesn’t quite know when to end, and it runs out of steam before it’s over. But it has enough bursts of hilarity sprinkled throughout it to be worth seeing, particularly if you enjoy ribald tales of rock ‘n’ roll excess. And don’t we all?

B- (1 hr., 49 min.; R, pervasive harsh profanity and vulgar dialogue, a lot of strong sexuality and nudity.)