They always had chips on their shoulders, a grievance born of their distinctive authorship mixed with the civic pride of scrappy underdogs. They were André “3000” Benjamin and Antwan “Big Boi” Patton, but they went by an increasing array of colorful names—like Possum Aloysius Jenkins and Daddy Fat Sax—which seemed to exist only to expand minds and expectations while capturing the ideas that emanated from their craniums. They had emerged from southwest Atlanta with styles that were unforeseen, but quickly copied—the Kangol hats they wore in the video for “Southernplayalisticadillacmuzik” were soon seen atop the domes of Sean “Diddy” Combs and the Notorious B.I.G. after having been out of vogue for years. On the intro to Stankonia—their fourth album, a thrill-pushing auricular splattering of mindfunks and ideascapes—they mimicked those copying them by playfully reinterpreting the Atlanta “bounce” that had been spreading as the distraction of babies. Big Boi exhaled smoke and lamented, “Niggas ain’t even from the A-Town.”

Identity and location—and defining and observing the two on their own terms—have always been key with OutKast. All of their albums began with a disembodied intro track as a prelude, followed by a State of the OutKast declaration that proved that, as André would famously go on to say at the 1995 Source Awards, “the South got something to say.” Tellingly, André confessed, “I gots a lot of shit up on my mind,” on “Myintrotoletuknow” from their 1994 debut Southernplayalisticadillacmuzik. Their voices spat out harsh rhymes and stretched out melodic moments, but they also spoke about things widely and deeply, respecting and commenting on everything going on hip-hop, largely by ignoring everything going on in hip-hop. Their sonic brashness and directness had Public Enemy’s Chuck D in its DNA, their fashion had antecedents in the Grandmaster Flash & the Furious Five meeting Afrika Bambaataa’s Soul Sonic Force, the subversive whimsy of De La Soul and A Tribe Called Quest were their forebears, giving the group a musical intensity and breadth incomparable to any other major hip-hop act before or since. Those are weighty statements, but OutKast was OutKast—singular, inimitable, and unpredictable.

Their debut was an album bursting with the funk descended from the Isley Brothers, Isaac Hayes, and Curtis Mayfield in a way that was smoother than Dr. Dre’s G-funk stylings, more organic than Puff Daddy’s wholesale sampling of ’80s R&B, and more fluid and adventurous than hometown icon Jermaine Dupri’s sleek soul and pop arrangements. It was the music of Southern hip-hop, the “country rap tunes” pioneered by the late Pimp C, outfitted to a weary worldview that was cautious and specific about local dealings and paranoid about the greater world, but ultimately hopeful on universal levels—or, at least as hopeful as “Crumblin’ Erb” while “niggas killin’ niggas” can be.

Southernplayalisticadillacmuzik was a revelation to hip-hop: Two dope boys in a Cadillac rapping just as well as, if not better than, just about anyone around them, sharing untold tales of Atlanta slums and Georgia red clay and opining on race in a way that introduced the concept of the Dirty South a year before they’d give it a name with the Goodie Mob. OutKast’s arrival was as eye-opening as N.W.A.’s had been in the late ’80s and their next project, ATLiens (1996) quickly vaporized any notions of sophomore slumps song-by-song, rhyme-by-rhyme. With their third album, Aquemini (1998)—a total fuck-you to any ideas of limitations on what a street-rooted hip-hop album could sound like, think like, and talk about—they ascended to rare air: musical acts who have been able to pull off a hat-trick of commercial and critical hits with their first three releases.

In this way, 2000’s Stankonia was set up to be a victory lap—the group really had nothing left to prove. Each album had further refined their mastery; each one was a tour de force in its own right. But where Aquemini seemed to be rejecting most radio leanings with sprawling jam-session numbers like “SpottieOttieDopaliscious,” “Liberation,” “Synthesizer,” and “Chonkyfire,” Stankonia found OutKast catering to a mass market without seeming to give it much thought. The album’s two most indelible hits—“So Fresh, So Clean” and “Ms. Jackson”—are unrepentant earworms that feel like natural extensions of the group’s sound, not crossover attempts. Both songs are full of layered and complex intonations: “So Fresh” simply speaks on haberdashery and hoes, while “Jackson” went on to win a Grammy, despite being a somewhat heady and sincere dedication to their baby mama’s mamas. Produced by their longtime collaborators and mentors Organized Noize, “Jackson” is one of the best radio singles they’ve ever produced as a duo.

It has to be mentioned that the group, along with their longtime DJ, Mr. DJ, had begun handling the bulk of their production with Aquemini and it sounded as if their longtime producers, Organized Noize—who had stunned on Goodie Mob’s debut, created one of TLC’s defining songs with “Waterfalls” and produced En Vogue’s biggest hit, “Don’t Let Go (Love)”—had actually been holding the duo back musically. Stankonia was an orgy of sonics leftover from Lee Perry’s Black Ark and George Clinton’s Mothership that sounded like drugs without sounding druggy. It was the acoustics of outer space talking about inner spaces; a self-driving Tesla in the body of a Cadillac Fleetwood; it was Wakanda. It’s no coincidence that former OutKast satellite Killer Mike’s group with rapper-producer El-P, Run the Jewels introduced the fictional nation in the first trailer for Marvel’s Black Panther—OutKast was at once retro and futuristic, veteranized and new school, otherworldly yet street, out of time and timeless, and their impact is evident in the biggest rap acts of today, from Migos to Kendrick Lamar.

There is so much going across Stankonia—the coordinated confetti of noises on “Gangsta Shit,” the uneasy meditation of teen pregnancy that is “Toilet Tisha,” the playful lasciviousness of “I’ll Call Before I Come,” the melodic menace of “Red Velvet,” the skits that spoke in metaphors to the subconscious via hood tongues, the arrangements and progressions that felt capricious, but totally natural. The backing tracks weren’t soundscapes as much as they are aural murals graffitied on the cosmic underpasses where abandoned tricked-out space shuttles rest, stripped of their Brougham rims. It was music that was tangential to crunk, a predecessor to trap, indebted to hip-hop, electro, funk, rock, and anything alternative—the type of music that usually succeeds on intellectual levels and rewards nerds, but not readily equating to an album that would sell more than 4 million copies. Yet OutKast is probably best defined by defying parameters and expectations.

Stankonia is easily the group’s most expansive and abrasive effort. It’s more accomplished than their biggest seller, the double-disc Speakerboxxx/The Love Below, which lacks the tension and dichotomy of André and Big Boi locked in a studio, warring with each other and themselves to the extent that created numbers like “Humble Mumble,” Stankonia’s breakbeat-ish, Caribbean-tinged track where Big Boi admonishes a simp with “Sloppy slippin’ in your pimpin’, nigga/You either pistol whip the nigga or you choke the trigger,” before André recalls speaking with a rap critic: “She said she thought hip-hop was only guns and alcohol/I said ‘Oh, hell naw!’/But, yet, it's that too.”

OutKast had always consisted of a politically conscious pimp and a spiritual gangsta, but on Stankonia, those identities came to the fore with a greater distinction that paradoxically allowed them to sound closer together than they had since their inception—even as André sat out songs like “Snappin’ & Trappin’” and “We Luv Deez Hoez.” On Stankonia’s first proper song, “Gasoline Dreams” Big Boi raps about their clout and the limits thereof—“Officer, get off us, sir/Don’t make me call [my label boss] L.A. [Reid], he’ll having you walking, sir/A couple of months ago they gave OutKast the key to city/But I still gotta pay my taxes and they give us no pity”—while André throttles out a brainy hook: “Don’t everybody like the smell of gasoline?/Well burn, motherfucker, burn American dreams.”

Stankonia is an album about many things and full of epigrams; so ahead of the curve that one of its many double entendres—“I got a stick and want your automatic”—is now a bona fide triple entendre. It’s about sounds as smells and music as sex, but mostly it’s about two black kids from Southwest Atlanta, boogieing with chips on their shoulders, making Molotov cocktails of songs that sound like a revolution’s afterparty. It’s peppered with personal narratives and small slips of autobiography, and it tackles big ideas both directly and obliquely. But, ultimately, it sounds like two artists going pop on their own terms while trying to make sense of, and change, the world around them. Closing in on two decades after its release, Stankonia remains loud as bombs over Baghdad and humble as a mumble in the jungle.