The Roland TR-808 drum machine might be the most influential musical invention of the last 40 years. Its clicky, hypnotic percussion can be heard on everything from Marvin Gaye’s “Sexual Healing” to Phil Collins’ “Another Day in Paradise” to Lil Jon and Usher’s “Yeah!” to this month’s No. 1 song in the country, Rae Sremmurd’s “Black Beatles” and a whole world in between. Only 12,000 TR-808s were produced by Roland between its debut in 1980 and unceremonious discontinuation in 1983, but, to paraphrase the old quip about The Velvet Underground & Nico, seemingly everyone who bought one fired their drummer.

The miraculous little machine is now the subject of a fittingly quirky and lively documentary, 808: The Movie, which premieres on iTunes this Friday. (For Apple Music subscribers, it has already been made available to stream for free.) From a musical standpoint, the film takes as its origin story Afrika Bambaataa and the Soulsonic Force’s 1982 classic “Planet Rock,” a seven-and-a-half–minute maelstrom of funk that changed popular music. “Planet Rock” was not the first hip-hop hit, but no recording prior had so boldly evinced the gathering revolution the genre was about to unleash on the world. Coursing underneath Bambaataa’s pastiche of Kraftwerk, George Clinton, and other extraterrestrial encounters was a drum part unlike anything ever heard before. Pounding, rattling, throbbing, jittering, it seemed to contain all the ecstasy of the dance floor in eight bars, looped into perpetuity.

“Planet Rock” didn’t so much put the 808 on the map so much as it reoriented an entire world of post-disco dance music around it. Ironically, the 808’s signature achievement came in the form of something it completely failed to do: namely, sound like an actual drum kit. The 808’s sounds were riotously inauthentic: canned hand claps, a cowbell that sounded like a touch-tone phone, a bass drum that sounded like Charlie Brown’s parents having sex. We’ve now become so used to these sounds that it’s easy to lose sight of the sheer strangeness they wrought upon arrival. It hardly feels like a coincidence that the 808 emerged from Japan the same year as another seminally bizarre early-’80s creation, Pac-Man.

The 808 was originally designed to help musicians make home demos, but like all great musical inventions, it only became indispensable once the right people started using it wrong. Most commonly this involved souping up that bass drum to inadvisable degrees, such as on T La Rock’s 1984 classic “It’s Yours,” the record that launched Rick Rubin’s career and ultimately led to the founding of Def Jam Recordings. 808: The Movie features on-camera testimonials from both T La Rock and Rubin, each of whom reminisce about how Rubin used no fewer than six bass drum tracks on the record, creating a sound powerful enough to literally blow out speakers. Just two years later Rubin produced the Beastie Boys’ Licensed to Ill, the first hip-hop album to top the Billboard album charts. One of its most beloved tracks, “Paul Revere,” featured an 808 recorded backwards. (Mike D and Ad-Rock insist the idea was in fact the late MCA’s.)

808: The Movie is narrated by Zane Lowe, but its on-screen interviews are its highlights, featuring the likes of Questlove, Lil Jon, Richie Hawtin, Damon Albarn, Diplo, Pharrell, Jimmy Jam and Terry Lewis, and many more. (Afrika Bambaataa appears as well, although the documentary was finished before the recent sexual abuse allegations against him emerged.) There’s a giddy and shaggy wonkiness to many of the interviews, as though the subjects can barely believe someone’s filming them geek out over a drum machine. Perhaps the film’s best sequence features club legend Strafe re-creating his 1984 classic “Set It Off” in a present-day studio with just an 808 and a synthesizer.

808: The Movie is most concerned with the 1980s, which makes sense given that the device’s full story is far too expansive for a single film, although the film misses some opportunities to explore the 808’s continuing popularity—indeed, in the past 10 years, the 808’s sounds may have become more ubiquitous than ever before. The film makes only passing reference to the 808’s centrality to Southern trap music, and it never even mentions Kanye West’s wildly influential 2008 album 808s and Heartbreak, an explicit love letter to the device. (If you say 808 to a present-day college student, you’re far more likely to get a disquisition on West than on “Planet Rock”—trust me, I know.)

808: The Movie works best as an ode to the instrument, and like most hagiographies, it’s a bit light on context. For instance, barely any other drum machines are even mentioned in the film, most notably the Linn LM-1, which was arguably even more ubiquitous in mainstream ’80s pop than the 808. The lack of context feels like a missed opportunity to address what should be one of the film’s central questions: Why did the 808 become so popular? One reason is that it was relatively cheap. In the early 1980s, an LM-1 retailed for $5,500, while a new TR-808 could be acquired for a little more than a grand. Another is that, for all its quirky and esoteric design, the 808 is remarkably easy to use and worlds of fun to mess around with, with its dancing flashing lights and color-coded buttons just dying to be pressed. Even more importantly, it’s remarkably easy to program: Prior to the LM-1 and the 808, many drum machines came with preset rhythms that weren’t modifiable outside of tempo. On the 808 you can make your own patterns and your own tempos—rather than simply being a tool of recreation, it’s a tool of creation.

But not without its limits: Due to the fact that, as Roland founder Ikutaro Kakehashi puts it in the documentary, memory in 1980 was expensive, any 808 pattern necessarily maxes out at 32 units of rhythm (in a standard 4/4 time signature, eight bars). Much like the chintzy falseness of its sounds, however, the bug quickly became a feature. In the 1980s, hip-hop, house, electro, techno, and other descendants of disco were preoccupied with rhythmic repetition, so those eight-bar units became veritable playgrounds for invention and creativity, the devices’ creative capacities pushed to their breaking point and beyond. One of the most significant epistemic shifts in late-20th-century popular music was the move from thinking of music in terms of harmonic progressions and conventional song structure to thinking of music in terms of sequences, discrete passages of sound and time to be repeated and revised ad infinitum. More than any other instrument of its time, the 808 both enabled and catered to this shift.

808: The Movie is a deeply geeky film—anything less would be a betrayal of its subject. If you’re not as fascinated by drum machines as its filmmakers and interview subjects (or, full disclosure, this reviewer), you might find its one note a bit repetitive. But as long as you’ve got rhythm, who ever needed more than one note anyways?