We throw around the phrase "party like a rock star" so casually, it's a little surprising that so few films have gone to the trouble of illustrating the notion. Nicholas Stoller's Get Him to the Greek does such a thorough job, I can't imagine anyone else will take a crack at it anytime soon. A "spinoff" (God, that always sounds so unwieldy) of Stoller's 2008 comedy Forgetting Sarah Marshall, Greek takes the supporting character of womanizing rock star Aldous Snow (Russell Brand) and places him center stage.

The clever, compact opening sequence brings us up to date: after the spectacular failure of his self-important, exploitative album African Child (the picture opens with a related fake-out that is so well done, I legitimately thought they'd threaded up the wrong print) and the loss of his longtime girlfriend and collaborator Jackie Q (Rose Byrne), Snow has fallen off the wagon, and in a truly spectacular fashion. He's more of a self-indulgent train wreck than an artist these days, but when high-powered music executive Sergio Roman (Sean "P. Diddy" Combs) starts grilling his staff for new ideas, junior executive Aaron Green (Jonah Hill) puts one out there--the tenth anniversary of the celebrated Greek Theater concert by Snow and his band Infant Sorrow is fast approaching, so an anniversary concert (with tie-in pay-per-view, DVD, and CD) could be just the boost that both the artist and the label need. For his trouble, Aaron is given an impossible job: He has 72 hours to retrieve the rock star from London, take him to New York for a promotional appearance on the Today show, and then get him to the Greek for the big show.

The ticking clocks of those deadlines help give the picture a pulse and a good-natured, fast pace. Stoller is not the most inventive director--too many of his dialogue scenes fall into easy TV-style coverage, and when things go batshit insane in the Las Vegas suite late in the film, the chaos is too orderly, too controlled to cut loose the way it should. But he's good at creating a level-headed insanity, at setting up funny situations, putting broad but plausible characters into them, and following things through to their logical conclusions. His screenplay seizes on the most interesting beats of Jason Segal's script for Sarah Marshall--the later scenes, in which Snow was pulled out from his cheeky villainous construct and allowed enough complexity to give the central conflict some depth. It's easy to play the ridiculous navel-gazing twit (Eric Bogosian did a similar character, right down to the British ancestry and shallow charitable leanings, clear back in 1990's Sex, Drugs, Rock & Roll), but in the third act, as he sees through Sarah Marshall's petty jealousies or gives Peter some laid-back, good-natured advice, the character become unexpectedly likable and memorable. In Get Him to the Greek, Aldous Snow is a real character, with fleeting moments of doubt, bitterness, vulnerability, darkness. Stoller's writing, and Brand's playing, navigates those transitions gingerly without circumventing the character's explosive comic potential.

Jonah Hill manages to take what is basically a straight man role and spark it up with his tossed-off readings and wide-eyed wonder; his big, moony face is his best weapon here, particularly in an uproarious shot that dreamily tilts down to Aaron bouncing on the dance floor, intoxicated by his first, sublime taste of absinthe. Hill and Brand make for a good team, with their Mutt and Jeff looks, complimentary sensibilities, and well-matched rhythms. Hill's on-screen relationship with Elisabeth Moss (from Mad Men) is also surprisingly well-done; it looks at first to be another credibility-stretcher from the Apatow factory (one of these guys should have an average-looking girlfriend, just once), but there is a giddy, playful vibe to their interplay, and when he reminds her of who The Mars Volta is by hitting a remote and playing a perfectly chosen snippet (and seeming to sing along), we're sold. (Stoller also leans their relationship into an unexpected but explosively funny right turn in the third act.)

But Combs turns in perhaps the most entertaining performance in the movie--I again plead with him to quit his day job. As the seen-it-all music honcho, his straight-faced, barely-contained rage manifests itself in some of the best slow-burn comic acting this side of Edgar Kennedy. When he sits Aaron down and explains exactly how to handle the talent, he's practical and straight-shooting ("We don't lie to people," he explains, "we just believe invalid truths"), but he's got enough of a dangerous fire in his eyes (as he did in Made) that when he goes off the deep end in Vegas, you get why Aldous and Aaron run for the hills. The film also features a roll call of pop culture cameos (it's about the only film that could feasibly include both Paul Krugman and Pharrell), all of them in on the gag.

Get Him to the Greek hums right along, tackling its comic scenarios with wit and precision, and its throwaway gags are frequently just as funny as the big set pieces (Hill's Las Vegas heroin run takes what would be, in any other movie, a 20 minute sequence and compresses it into about 30 seconds of slam-bang hilarity). And mention should be made of the music, which is just well-crafted and catchy enough for Aldous's fame to be believable (I would totally have "The Clap" on my iPod), settling just on this side of parody. And what the hell, most pop music is self-parody these days anyway. If Get Him to the Greek doesn't quite match the emotional resonance of its predecessor, it more than tops it in comic ingenuity--and manages to get at something real and genuine about fame and fandom in its closing scenes. It's funny and sweet, and a damned good time besides.

Jason lives in New York. He holds an MA in Cultural Reporting and Criticism from NYU.