Outkast caused a critical tidal wave with last year's Speakerboxxx/The Love Below, but the real Dirty South masterpiece du jour is this left-field stunner from Cee-Lo. The former Goodie Mob mouthpiece has created an hour-long magic-carpet ride of shape-shifting sounds and sweat-dripping rhythms that rewrites the rap rule book. True to its title, Soul Machine invokes the spirit of James Brown, Al Green and George Clinton while remaining true to its hip-hop core. I am the music, Cee-Lo proclaims, and you don't doubt him for a second. Soul Machine is a sonic tour de force, bouncing from Motown R&B to Philly soul to Atlanta hip-hop in the blink of an eye. Unlike many recent rap efforts, the guest stars (Timbaland, Jazze Pha, Pharrell Williams) actually add something to the mix. Ludacris, who tends to follow the paycheck wherever it may roam, finds his niche on "Childz Play," a hot-stepping ditty that makes full use of Luda's over-the-top personality without steamrolling into overkill. Overseeing the proceedings is Cee-Lo, whose nasal whine and motormouthed verbal skills have never sounded sharper. Party jams, bump-and-grinders, breakup-to-makeup songs, space-age experiments, a capellas -- Soul Machine has it all. Outkast's André and Big Boi continue to rule the rap roost with a velvet fist, but Cee-Lo pushes their far-out concepts into previously uncharted territory.