Hip-hop is a fount of constant innovation woven into nearly every corner of American life. So don’t look for cohesion: Lean into the cacophony.Sean “Puffy” Combs in a celebratory mood. In the mid-1990s, labels like Bad Boy helped bring rap to the center of American culture.Johnny Nunez/GettyHip-hop is a wondrous and centerless tangle, ubiquitous even if not always totally visible.It is a fount of constant innovation, and a historical text ripe for pilfering. It is a continuation of rock, soul and jazz traditions, while also explicitly loosening their cultural grip. It is evolving more rapidly than ever — new styles emerge yearly, or faster, multiplying the genre’s potential. And it has impact far beyond music: Hip-hop is woven into television and film, fashion, advertising, literature, politics and countless other corners of American life. It is lingua franca, impossible to avoid.It is far too vast to be contained under one tent, or limited to one narrative. The genre is gargantuan, nonlinear and unruly. It has its own internal quarrels and misunderstandings, and its stakeholders are sometimes friends and collaborators, and sometimes view each other warily.So when trying to catalog hip-hop in full, it’s only reasonable to lean into the cacophony. The package that accompanies this essay does just that, collecting oral histories from 50 genre titans of the past five-plus decades. The number matters. It’s an acknowledgment that at 50 years old — a mild fiction, but more on that later — hip-hop is broad and fruitful, enthralling and polyglot, the source of an endless fount of narratives. Its fullness cannot be captured without sprawl and ambition. Many voices need to be heard, and they won’t always agree.Side by side, there are stylistic innovators, crossover superstars, regional heroes, micromarket celebrities. There are those who insist on their primacy and see themselves as a center of gravity, and those who are proud students of the game and understand their place in hip-hop’s broader artistic arc. There are those who are universally recognized, and those known mainly by connoisseurs. There are agitators and accommodationists. The revered and the maligned. Some even play with the boundaries of what rapping is ordinarily considered to be.All taken together, these artists form a family tree of the genre, one that highlights bridges between groups that are typically discussed separately, and that underscores the ways in which rappers — no matter the city they hail from, or the era in which they found their success — have been grappling with similar circumstances, creative questions and obstacles.The Cold Crush Brothers in the Bronx, 1979. Joe Conzo, via Easy A.D.These 50 histories detail hip-hop from countless vantage points: the past forward, and vice versa; the underground upward; the less populated regions outward; the big cities out into the suburbs. They tell the story of a makeshift musical movement that laid the foundation for the defining cultural shift of the past few decades.Fifty years ago, though, that outcome seemed fanciful at best. In the 1970s, Bronx block parties gave way to nightclubs, and talking D.J.s laid the foundation for dedicated M.C.s to begin taking over. Soon, the intrusion of capitalism removed and packaged the part of these live events that was the easiest to transmit: rapping.Then it was off to the races. By the mid-1980s, the hip-hop industry was a small club but big business, as audiences around the country were primed by the commercial release of recordings from countless New York artists. A wave of soon-to-be-global stars arrived: Run-DMC, LL Cool J, the Beastie Boys. Hip-hop became worldwide counterculture.Run-DMC in 1985, onstage in Providence, R.I.John Nordell/Getty ImagesBy the dawn of the 1990s, it flowered everywhere in this country — the South, the West, the Midwest — and seeped into the global mainstream. In the mid-90s, thanks to the work of Biggie Smalls and Puffy, Tupac Shakur and Dr. Dre, Bad Boy and Death Row, it became the center of American pop music, despite resistance from those convinced rock was destined to forever reign supreme.Into the 2000s, the genre’s power center shifted from the coasts to the South, where the genre was flourishing (largely away from the scrutiny of the major labels) in Miami, Houston, Virginia, Atlanta and Memphis. 2 Live Crew, the Geto Boys, Missy Elliott, Outkast, Three 6 Mafia — each had absorbed what was being imported from the rest of the country and created new lingo and sonic frameworks around it. Hip-hop was becoming a widely shared language with numerous dialects.T.I. onstage in his hometown, Atlanta, in 2005.Ray Tamarra/Getty ImagesAll the while, the genre was expanding, becoming more commercially successful and inescapable with each year. It became centrist pop, which in turn spun off its own dissidents: the New York and Los Angeles undergrounds of the 1990s; the progressive indie scenes of the 2000s; and the SoundCloud rap of the 2010s. In the past 20 years, hip-hop has been responsible not only for some of the biggest pop music of the era — Drake, Kanye West, Jay-Z, Cardi B — but its templates have become open source for performers in other genres to borrow from, which they did, and do, widely. Hip-hop became a crucial touch point for country music, for reggaeton, for hard rock, for K-pop and much more.What’s striking in the histories collected in this package is how no part of that ascent has been taken for granted. In every era, there were stumbling blocks. For each artist, there was a promise of a scene just out of reach. And for all of these rappers, that meant leaning in to a new idea of what their version of hip-hop could be, and hoping ears would meet them in this untested place.Missy Elliott performing in New York in 2012.Jerritt Clark/FilmMagic, via Getty ImagesThere is also the matter of untold history — to read these recollections is to be continually reminded of those who are no longer here to share their tales. There is a punishing catalog of before-their-time deaths just below these stories, a reminder that canons can’t include songs that never got to be made.As for the 50th anniversary, well, it is a framing of convenience. The date refers to Aug. 11, 1973, when DJ Kool Herc — in the rec room of the apartment building at 1520 Sedgwick Ave. in the Bronx — reportedly first mixed two copies of the same album into one seamless breakbeat. That is, of course, one way to think about hip-hop’s big-bang moment, but by no means the only one. If you think of rapping as toasting, or talking over prerecorded music, or speaking in rhythmic form, then hip-hop has been around longer than 50 years. Just ask the Last Poets, or DJ Hollywood, who would improvise rhymes on the microphone as he was spinning disco records. There are also, depending upon whom you ask, others who had previously mixed two of the same record.Kanye West’s Saint Pablo tour opener in Indianapolis in 2016.AJ Mast for The New York TimesBut the canniness and the cynicism of attempting to enshrine a date that everyone can stand behind reflects a darker and more worrisome truth, which is that, for decades, hip-hop was perceived as disposable, a nuisance, an aberration. Commemoration and enshrinement seemed far-fetched. For a long time, hip-hop had to argue for its rightful place in pop music, and pop culture, facing hostilities that were racial, legal, musical and beyond.Insisting that the genre has an origin point, therefore, is really just another way of insisting on its importance, its stability and its future. You can quarrel with the specific details — and many do — but not with the intent, which is to ensure that no one again overlooks the genre’s power and influence.That said, hip-hop was never going anywhere, because no style of pop music has been as adaptive and as sly. Hip-hop directly answers its critics, and it voraciously consumes and reframes its antecedents. It is restless and immediate, sometimes changing so quickly that it doesn’t stop to document itself. So here is a landing place to reflect, and a jumping off point for the next 50 or so years. More