One of the many beauties of hip hop is that it's constantly in conversation with other genres, whether due to sampling, collaboration, or just inspiration. Formed on a bedrock of R&B, funk, and disco samples, it quickly became more omnivorous, and many of its watershed moments have come when combined with other styles in new, unheard-of ways. Take Rick Rubin and Terminator X's mining of hard rock records in the '80s, Dr. Dre transforming P-Funk into G-Funk in the early '90s, Pharrell and The Neptunes bringing a wave of latin rhythms to early '00s radio, or Kanye West, Wale, and Kid Cudi merging the indie rock and blog rap scenes in the mid-'00s-- oftentimes, all it takes is making something previously thought of as uncool sound cool. Right now, the genre that hip hop's reinventing, and in turn, the genre that's reinventing hip hop, is jazz.

In what other era of rap would an astral-bound bass maestro like Thundercat be a prized collaborator? Or what about a music school nerd-type like Donnie Trumpet? Or Kamasi Washington, a saxophonist whose last album was three hours long? Thanks to To Pimp A Butterfly and SURF, we've seen a ton of artists (mostly from L.A. and Chicago) treat jazz like a living, breathing entity that can be put into conversation with hip hop. Mac Miller, Isaiah Rashad, Vic Mensa, Anderson .Paak, Ty Dolla $ign, and Mick Jenkins have all dabbled with it on recent projects, and as a result, squawking horns and free-jazz rhythms no longer seem that out of place behind 16s and traditionally-styled hooks. Modern-day hip hop is more in-touch than ever with the live instrumentation and formlessness of free jazz, but it's far from the first era of jazz-rap.

The closest thing to originators that the subgenre has is probably Gang Starr, who were already flipping Dizzy Gillespie tracks by 1988, and whose debut album had DJ Premier knee-deep in as many vinyl crates of jazz as he was in crates of the standard O'Jays and James Brown R&B fare. Around the same time, A Tribe Called Quest were using the everything-but-the-kitchen-sink approach while chopping samples for 1990's People's Instinctive Travels and the Paths of Rhythm, which pulled as much from rock and pop (Jimi Hendrix, Carly Simon, Little Feat, and Lou Reed all made the cut) as it did from R&B. But their next album, released 25 years ago today, would be the most singularly jazz-devoted rap album ever released at the time. It was called The Low End Theory, the title inspired by the sound of a jazz double bass, and it began like this:

"Back in the days when I was a teenager
Before I had status and before I had a pager
You could find the Abstract listening to hip hop
My pops used to say, it reminded him of Bebop
I said, 'Well, daddy don't you know that things go in cycles
Way that Bobby Brown is just amping like Michael'"

"Excursions" kicks off with one of Q-Tip's many references to jazz on the album-- see also: "Children of the jazz," "The house of the jazz," "The jazz can move that ass," "What's Duke Ellington without that swing?", and an entire song called "Jazz (We've Got)"-- but more importantly, those opening lyrics contain a cross-cultural mission statement. Bebop, a fast-paced, improvisation-heavy style of jazz that emerged in the 1940s, faced vehement criticism in its infant years due to chord progressions, tempos, and frequent key changes that were drastically different than those found in the prevailing big band music of the day. For instance, bandleader Tommy Dorsey once claimed that bebop "set music back twenty years," and music columnist Jimmy Cannon quipped in a New York paper, "Bebop sounds to me like a hardware store in an earthquake." Compare that to criticism of hip hop by people who don't view it as a valid form of art. Quincy Jones: "When you come from the era of Ray Charles, Billie Holiday, Ella Fitzgerald, Aretha Franklin, Frank Sinatra and Michael Jackson, it gets hard to get used to Lil Wayne." Type O Negative frontman Peter Steele: "It's bad poetry executed by people that can't sing. That's my definition of rap." 

The bebop and hip hop movements both represented such cataclysmic shifts in music that they prompted the age-old "this isn't art" and/or "my kid could do that" responses from critics and existing artists, almost always signs that the artform in question will prove revolutionary over time. Tip's dad recognized this shared attribute, as well as the similarities between jazz scatting and rapping, and Tip added another astute observation on top of that, positioning himself and his group as the new Charlie Parkers and Thelonious Monks of the late 20th Century. We see this type of cross-generational comparison all the time now in hip hop-- Future Hendrix, "Black Beatles," "Cooler than Freddie Jackson sippin' a milkshake in a snowstorm," etc.-- but in '91, it was game-changing. 

Not only did Tribe sample Eric Dolphy, Cannonball Adderly, Art Blakey, Lonnie Smith, Weather Report, and plenty of other jazz greats on TLET, but they got legendary double bassist Ron Carter to play on "Verses From The Abstract," yet another sign of Tip's admiration of the genre. You can still hear definite earmarks of R&B on the album, namely on "Show Business" and "What?", but the jazzy elements outnumber them. On tracks like "Vibes And Stuff" and "Jazz (We've Got)", traditional grooves are replaced by an off-kilter bounce, angular as it is smooth, that would go on to inspire fellow jazz heads Madlib and (future Tribe collaborator) J Dilla. So purposeful was Tribe's devotion to jazz's bebop and harp bop offshoots that the "Jazz (We've Got)" single's artwork mimics packaging of old singles released by Blue Note Records, one of the key labels of those genres' golden ages. 

While it's hard to pinpoint the exact influence The Low End Theory had across hip hop in the early '90s, what is clear is that many jazz-rap fusions popped up almost immediately in its wake. Before 1992 was out, Digable Planets had released their debut single "Rebirth Of Slick (Cool Like Dat)", which also sampled Art Blakey, and a year later, British group Us3 hit the charts in the states and across Europe with "Cantaloop (Flip Fantasia)", which was built around a Herbie Hancock sample and (surprise, surprise) also included an Art Blakey sample. Even some of those artists sampled began to take notice and experiment with hip hop. Hancock's 1994 album Dis Is Da Drum featured hip hop-inspired beats, and jazz legend Miles Davis even teamed up with Easy Mo Bee for his 1992 crossover attempt Doo-Bop. It'd be far-fetched to suggest that all of these were directly inspired by TLET, but comparing the jazz-rap scene's status before and after the album's release, it seems like September 24th, 1991 was the genre's Kitty Hawk moment. 

In the long-term, the album's more provably influential, giving a name to the weekly club night that's the epicenter of the Brainfeeder label started by Flying Lotus, and everyone from BADBADNOTGOOD to Kendrick Lamar to Robert Glasper has named TLET as a key inspiration. Tribe may have not been the first to, as MF Doom once put it, "flip an old jazz standard," but they were the first rappers to immerse themselves in the genre, not only mining records for drum breaks and melodies, but collaborating with one of its greats, viewing it in a similar context to their own cultural movement, and mimicking its aesthetics. Any time someone throws a squealing horn onto a track, or frees drums from standard quantization in 2016, it's impossible to not think about what Tribe did 25 years ago.