Even compared to their already excellent and forward-looking catalog, OutKast's sprawling third album, Aquemini, was a stroke of brilliance. The chilled-out space-funk of ATLiens had already thrown some fans for a loop, and Aquemini made it clear that its predecessor was no detour, but a stepping stone for even greater ambitions. Some of ATLiens' ethereal futurism is still present, but more often Aquemini plants its feet on the ground for a surprisingly down-home flavor. The music draws from a vastly eclectic palette of sources, and the live instrumentation is fuller-sounding than ATLiens. Most importantly, producers Organized Noize imbue their tracks with a Southern earthiness and simultaneous spirituality that come across regardless of what Dre and Big Boi are rapping about. Not that they shy away from rougher subject matter, but their perspective is grounded and responsible, intentionally avoiding hardcore clichés. Their distinctive vocal deliveries are now fully mature, with a recognizably Southern rhythmic bounce but loads more technique than their territorial peers. Those flows grace some of the richest and most inventive hip-hop tracks of the decade. The airy lead single "Rosa Parks" juxtaposes front-porch acoustic guitar with DJ scratches and a stomping harmonica break that could have come from nowhere but the South. Unexpected touches like that are all over the record: the live orchestra on "Return of the 'G'"; the electronic, George Clinton-guested "Synthesizer"; the reggae horns and dub-style echo of "SpottieOttieDopaliscious"; the hard-rocking wah-wah guitar of "Chonkyfire"; and on and on. What's most impressive is the way everything comes together to justify the full-CD running time, something few hip-hop epics of this scope ever accomplish. After a few listens, not even the meditative jams on the second half of the album feel all that excessive. Aquemini fulfills all its ambitions, covering more than enough territory to qualify it as a virtuosic masterpiece, and a landmark hip-hop album of the late '90s.