At least they haven't quit their day jobs. Not that they haven't given that some thought.

Andre Benjamin and Antwan A. Patton, aka Andre 3000 and Big Boi, funkmeisters of OutKast, have been dipping their toes in the cinema pool for a couple of years. But whatever charm and possibilities they displayed in "Be Cool" (Andre) or "ATL" (Big Boi) are pretty much frittered away in Idlewild, a misguided period-piece musical about gangsters, illegal "hooch," "floozies" and music that is almost entirely unlike jazz.

Benjamin, the one with the playful persona who used to urge us to "shake it like a Polaroid picture," is Percy, a pianist-songwriter who fronts the juke joint band where Rooster (Patton) holds forth. They serve up funky hip-hop to Prohibition-era Georgians at "Church," their speakeasy. Rooster drinks and cheats on his family and lives large, but Percy works quiet days in daddy's mortuary (Ben Vereen is his father) and hides behind his piano on stage.

Then, benign mob boss Spats (Ving Rhames) is knocked off by babyfaced killer Trumpy (Terrence Howard), and the boys have to scramble to find ways to avoid ending up dead from unpaid mob debts.

And there's the new singer, Angel (Paula Patton), fresh in from St. Louis. She sets her sights on Percy.

A few production numbers, a few shootouts, a little sex, a few funny surreal conversations between Rooster and the rooster embossed on his drinking flask, and "Idlewild" plays out pretty much the way every mobsters-nightclubs movie has gone since the 1930s.

The music isn't remotely right for the era, which isn't as huge a problem as you might expect. The songs aren't lyrical, the singing not polished the way band singers of the day were. All the guys had to do was become crooners, like Bing or The Mills Brothers. Big Boi just raps, as if that sort of performance would draw an audience of more than four in 1931.

The bigger problems are the characterizations. Patton's playing a sharp-dressed hustler, which is kind of fun. Benjamin is playing meek, which isn't interesting to watch and which he's terrible at. His mumbling, eyes downcast low-energy turn may be the worst performance of the summer, worse even that M. Night Shyamalan's little "Lady on the Water" ego trip.

The direction, by OutKast's music video director, Bryan Barber, has real verve in the dance scenes, shootouts and car chases.

He plays around with slo-mo, pulling closeups out of freeze-frames, and builds one song around a wall of funkadelic cuckoo clocks.

But his efforts to razzle-dazzle in the dramatic or erotic scenes fall flat. And his script is painfully trite, overlong, and utterly reliant on his stars' musical charisma, which he has muted almost all the way through the movie.

The third-act appearance of an Every African-American, played by Cicely Tyson, is as embarrassing as Benjamin's attempt to croon over the closing credits.

Maybe the bad news about "Idlewild" is good news for OutKast fans. They won't be able to hang up the funk after all.