For such an acclaimed and celebrated album, Illmatic runs the risk of being misunderstood, even underrated. Most agree it’s one of the most influential hip-hop discs of the post-Nation of Millions/Chronic era, but when writers get down to specifics about what makes it so terrific, they tend to devolve into generic talking points: Illmatic, we’re told, was part of New York’s rap revival of the 1990s; it featured indelible you-are-there storytelling about life in the projects; and it heralded the rise of a gifted new lyricist, the then-20-year-old Queens resident Nas. All of that’s true, but 20 years after its making, Illmatic transcends biographical details. There is something larger, more ineffable, about its brilliance. We keep listening because we hope we’ll put our finger on it. But we never do.

Pity, then, the makers of Nas: Time Is Illmatic, which opens theatrically October 1 before becoming available on VOD and iTunes two days later. The documentary means to explore the roots of the album’s genesis, interviewing Nas as well as the producers, friends and family who helped shape the record’s musical and lyrical direction. We learn the important bullet points of Nas’s backstory. Born Nasir Jones in September 1973, he grew up the son of Olu Dara, a jazz musician who didn’t stick around long to raise Nas or his brother Jabari. Coming of age in New York���s drug- and crime-ridden Queensbridge projects, Nas witnessed his share of the gangster lifestyle that was being flaunted in hip-hop in the late ‘80s and early ‘90s, channeling his observations into Illmatic’s 10 sober tracks.

Directed by One9 and written by Eric Parker, Nas: Time Is Illmatic is a breezy once-over of how Illmatic came into being. But while it’s customary for such fan items to play like a feature-length ad for its subject, Time Is Illmatic is striking in that it accidentally underlines the reasons why the album, and its maker, aren’t more major than they are. Nas’s childhood traumas are tragic — a broken home, the loss of a close friend (Will “Ill Will” Graham) to violence — but as presented in the documentary, they don’t feel necessarily more compelling than the dozens of other depressingly familiar obstacles faced by other future hall-of-fame rappers. Unlike contemporaries such as the Notorious B.I.G. or Jay-Z (who would engage in a very public beef with the Illmatic auteur a few years later), Nas never flashed undeniable charisma or blinding star power. In Time Is Illmatic, he comes across as the same shy, monosyllabic man he’s often seemed in interviews. For all of his bluster and dazzling word play on record, Nas isn’t a particularly dynamic individual in the room, which hurts him in a culture that values oversized personalities such as Eminem and Kanye West who give good quote.

Frustratingly, Time Is Illmatic isn’t much better at explaining precisely why we still care about the album after all this time. Hearing from Alicia Keys, Pharrell Williams and Erykah Badu is helpful, but not illuminating: Illmatic was an influence on their work, they say, although nobody really pinpoints a reason beyond suggesting that Nas is honest in his lyrics. The filmmakers basically take it for granted that we know Illmatic is exceptional and leave it at that, letting snippets of songs and sparse in-the-studio anecdotes stand in for analysis.

Though autobiographical and clearly a product of prolonged exposure to New York’s toughest neighborhoods, Nas’s debut doesn’t hit the ear as a historical document or societal time capsule. Truth be told, Illmatic isn’t just one of hip-hop’s great albums — it’s one of the art form’s most plainly gorgeous.

When Illmatic hit stores in April 1994, it closely followed in the footsteps of Wu-Tang Clan’s Enter the Wu-Tang (36 Chambers) and preceded the release of Ready to Die, from Biggie. At a time when the sun-splashed paranoia of West Coast gangsta rap (in the form of Dr. Dre and Tupac Shakur) was shifting hip-hop’s center of gravity, these three New York debuts emerged within the span of 12 months, each offering their own steely, grim report on black crime and institutional racism. For Wu-Tang Clan, poverty and drug dealing were transformed into kung-fu mythology, while the Notorious B.I.G. made us love his morally questionable thug tales by plying us with confessional, funny lyrics and fiendish funk hooks. Appropriately for a famously introverted figure, Nas’ Illmatic featured fewer frills than its competitors, the songs blunt and immediate.

Running just under 40 minutes, Illmatic is a taut jewel in an era of self-congratulatory excess, hour-plus albums that were padded with (subpar) skits and too many tracks. Despite being overseen by a collection of who’s-who producers, including DJ Premier and Pete Rock, Illmatic holds together as a cohesive whole without the benefit of an overarching narrative or thematic arc. Nas didn’t exactly break new lyrical ground but, for one CD, he was able to write definitive versions of popular hip-hop tropes. Others had embraced the hedonistic fatalism of Al Pacino’s Scarface, but no one had thought to take a piano loop from Ahmad Jamal and twist it into “The World Is Yours,” a sweeping, jazzy salute to fallen comrades (including Ill Will) that pays tribute to Gandhi while imagining using dollar bills to light big-ass cigars. Black-on-black violence was a familiar topic, but the minimalism of “N.Y. State of Mind” gave the subject matter a raw urgency, Nas oscillating between Big Willie fantasies and grim portraits of lost souls: “I know this crack head who said she’s got to smoke nice rock,” he raps, “and if it’s good, she’ll bring you customers in measuring pots.”

Nas’ words, bouncing off the tense beats like racket balls, displayed verbal dexterity with zero flair. Lacking the vocal color of MCs like Chuck D or Slick Rick, Nas has never succeeded on the strength of his personality. Even on the closing track, the boastful “It Ain’t Hard to Tell” (with its sampling of Michael Jackson’s romantic “Human Nature”), he can’t quite savor his braggadocio. Comparing his badass self to Sylvester Stallone in Cobra and the wrestler the Iron Sheik, Nas attacks the mic with such seriousness that you could almost miss the cleverness of his rhymes. It’s possible Nas missed it, too: Cramming in as many words per line as he can, the rapper resists stepping back to regard his own lyrical fluidity, instead always leaning forward to deliver the next verse, the next killer sound bite.

And then there was the music itself. At its best, Illmatic merged the strengths of Enter the Wu-Tang and Ready to Die, focusing on eerily spectral hooks to create an almost surreal, heightened portrait of ghetto life that felt dramatic without being romanticized. Illmatic crafted an alluring, protective shield around the pain Nas witnessed, convincing us that he’d managed to make something beautiful out of a life that often wasn’t.

Don’t believe the hype that critics and writers were uniformly down with Illmatic from the beginning. Although it received a rare five-microphone rave from The Source, the album got stomped by Ready to Die at the 1995 Source Awards. When Spin put together its “90 Greatest Albums of the ‘90s” issue in 1999, Illmatic was nowhere to be found, although The Chronic, Enter the Wu-Tang and Ready to Die all placed high. That litany of disses could be encapsulated by a comment made by Questlove, the drummer and spiritual leader of the Roots, who remembered in his 2013 book Mo’ Meta Blues seeing Nas looking dejected during the 1995 Source Awards. “That was the night Nas’s Clark Kent turned into Superman,” Questlove wrote, “the night this mild-mannered observer realized he had to put on a suit and try to fly. But maybe he didn’t have flying power in that way. When he released his next record, It Was Written, there was debate over whether he was following his own course or trying to be Biggie.”

Nas never succeeded in being Biggie, which is fortunate in part since he’s still among the living. Instead, he’s remained Clark Kent, delivering solid, sometimes brilliant albums that have failed to capture a moment as startlingly as Illmatic did. But where the culture once overlooked him, it now seems to have come around. In 2005, when Spin published a list of the best albums of the last 20 years, Illmatic landed at No. 17.

The real shortcoming of Nas: Time Is Illmatic is that it’s almost superfluous. No movie can tell us why this album is so great — that’s what the album is for.

Tim Grierson is a film and music critic who writes for Screen International, Deadspin, Paste, Rolling Stone and The Dissolve. He tweets at @timgrierson.