When is a sequel not truly a sequel? When it's "Get Him to the Greek," a spin-off feature pulled from the womb of the uproarious 2008 comedy, "Forgetting Sarah Marshall." Knowledge of "Marshall" isn't necessary to partake in the "Greek" debauchery, but it helps to locate the proper mood for this frequently hilarious, oddly poignant road movie, which once again captures actor Russell Brand in his most appealing form: tongue-floppingly lascivious.

A lackey at Pinnacle Records, Aaron Green (Jonah Hill) dreams up a grand idea to return rocker Aldous Snow (Russell Brand) to the stage for a special anniversary concert after years of partying, a tumultuous relationship with girlfriend Jackie Q (a shockingly silly Rose Byrne), and various misguided musical efforts have tarnished his legacy. Exciting his boss Sergio (Sean Combs, who kills here), Aaron is sent off to London to retrieve Aldous, bringing him to New York City for a television appearance, and then off to Los Angeles for a triumphant concert at the legendary Greek Theater. However, in the company of a known hedonistic monster, Aaron is dragged along on a wild adventure that involves raucous parties, tempestuous family reunions, and a vast reservoir of paranoia.

Continuing on from his "Marshall" directing duties is Nicholas Stoller (who also scripts), designing a "My Favorite Year" odyssey for poor, hapless Aaron; it's a festival atmosphere that highlights the young go-getter attempting to tame a well-documented rock rapscallion on the way to a stage redemption he hasn't exactly earned. The formula is familiar, yet the results are often startlingly hilarious, bouncing between sly industry gags and drippy, winningly awful gross-out humor. The mix is volatile, but that's exactly what electrifies "Greek" beyond its ho-hum origins, handing off these ripe, drug-fueled comedic situations to the capable cast, who improv and shuffle their way around the frame while Stoller captures the throttled silliness.

Brand is ideal for this type of material, possibly pulling from his own life experiences to articulate Aldous's endless prodding personality and penchant for chemical excess. He's a more sideswiped character than the one introduced in "Marshall," with the rocker down on his luck, looking for some form of salvation, finding a white knight of sorts in his easily manipulated handler, Aaron. Brand is a scream, bouncing off Hill beautifully as the script gently accelerates the nonsense while introducing some sensitivity as Aldous deals with the various domestic issues (daddy, baby, lady) that weigh him down. Returning to the motor-mouthed, spit-slicked persona that's served him well, Brand sustains the picture's sense of humor, best played when Aldous guides Aaron through some heinous acts of overindulgence. In what amounts to the straight man role, Hill supplies the disbelief and gluttonous imbibing with ace timing, perfectly embodying a humble, whipped man blasted in the face by waves of music industry excess.

While "Marshall" employed the nightmarish qualities of an emotional breakdown to cradle the laughs, "Get Him to the Greek" is more of an impulsive, slapstick creation, leaning on the snappy one-liner skills of the two leads, while Stoller dutifully sets the dominoes. It's broad, playfully bizarre moviegoing experience, sure to be one of the most agreeable comedies of the year.