Regarded by many as the greatest Southern rap album ever, 1998’s Aquemini is the connective tissue between Outkast’s beginnings as regional hip-hop heroes and the duo’s full-fledged pop stardom. While their first two LPs featured no shortage of André 3000 and Big Boi’s tongue-twisting rhymes and the Dungeon Family collective’s off-kilter beats (courtesy of Organized Noize and themselves), Aquemini was the creative leap forward that turned an already critically acclaimed group into thought leaders of the hip-hop avant-garde. Long jam sessions with a rotating cast of live musicians yielded their lushest music and most adventurous arrangements to that point; lyrically, the pair began exploring different avenues of creative thought. But instead of breaking up the band, they leaned into that duality while giving the music a singular cohesive vision. Big Boi (an Aquarius) remained vivid in his tales of harsh street realities, while André 3000 (a Gemini) began embracing more conscious material and flights of kalimba. Together, as Big Boi raps in “Return of the ‘G,’” “We worked for everything we have and gon’ stick up for each other, like we brothers from another mother/Kind of like Mel Gibson and Danny Glover.” Produced mostly by the duo and Mr. DJ, Aquemini’s sound is a mix of the distinctly Southern and the distinctly alien. Nowhere is this more apparent than the single “Rosa Parks,” which is built on hollow snares and punishing bass but beams with earthy acoustic guitars and a harmonica solo courtesy of André’s stepfather, Pastor Robert Hodo. Or take the “Da Art of Storytellin’” suite: “Pt. 1” tells tales of earthly vice over a head-bobbing swirl, while “Pt. 2” speaks of the apocalypse through mountains of distortion. Elsewhere, slower songs like the title track, the indelible “SpottieOttieDopaliscious,” and the sprawling jam “Liberation” shimmer like an update on the opulent arrangements of Isaac Hayes or Earth, Wind & Fire. It’s an album that prophesied the future of Atlanta—a misunderstood scene that was once dismissed as “regional,” but eventually became the center of the rap universe itself.