NEW YORK, NY.- Gary Hustwit had a simple wish: to make a documentary about visionary musician Brian Eno. When that wasn’t possible, he devised a far less simple approach. He made 52 quintillion documentaries about Eno.

At a time when it seems like there’s a movie about every band that’s recorded even a 45, Hustwit’s “Eno,” which opened Friday, is unlike any other portrait of a musician. It’s not even a portrait, because it isn’t fixed or static. Instead, Hustwit used a proprietary software program that reconfigures the length, structure and contents of the movie.

“Every time it plays, it’s a different movie,” Hustwit told an audience in May at the film’s New York premiere. “I’m surprised every time I see it.”

His collaborator, digital artist and programmer Brendan Dawes, explained that because of the variables, including 30 hours of interviews with Eno and 500 hours of film from his personal archive, there are 52 quintillion possible versions of the movie. (A quintillion is a billion billion.) “That’s going to be a really big box set,” Dawes quipped at the premiere.

Movie theaters are still guided by “a 130-year-old technical constraint,” Hustwit said over lunch the next day at a New York City restaurant. “We can use technology as a structural tool to do interesting things with the narrative. This idea that a film has to be set in stone and always linear is obsolete, I think. There’s another possible path here for filmmaking going forward.”

A generative approach to documentary is especially suitable for Eno, who has made generative music for years. (Despite the use of the word “generative,” artificial intelligence isn’t involved in either the film or the music.)

In 1972, as an original member of the unsurpassed British art-rock band Roxy Music, Eno was an immediate media phenomenon. He was a dolled-up, androgynous dandy in rouge and eyeliner, with a wardrobe of kimonos, butt-hugging cigarette pants and padded jackets adorned with animal feathers.

He left Roxy after two albums and started a solo career that anticipated punk and new wave. And he has produced or collaborated with Talking Heads, Devo, U2 and David Bowie, bringing experimental elan to pop music.

His interest in generative music was inspired by Steve Reich’s opus “It’s Gonna Rain.” Reich recorded a Pentecostal preacher on a San Francisco street corner, then duplicated a short passage and played it simultaneously on two tape recorders. Thanks to variations in motor speed, the twin loops gradually fall out of sync, building to a wild cacophony. The music “blew my socks off,” Eno said in a 1996 lecture.

Generative music, he explained then, is based on “a system or a set of rules which, once set in motion, will create music for you.” For his 1978 album “Music for Airports,” a founding document of ambient music, he recorded three simple melodies, each of a slightly different length, then allowed them to play in what mathematicians call incommensurable cycles, which never repeat.

“If you work in electronic music, Eno’s relevance is unavoidable,” said Carsten Nicolai, a German musician who records under the pseudonym Alva Noto. “He was very much ahead of his time. His first records are more than a half-century old, but they don’t feel old.”

Eno had contributed the soundtrack for Hustwit’s previous documentary, “Rams” (2018), a profile of German industrial designer Dieter Rams. But when the director proposed a movie about Eno, the idea was immediately shot down. It wasn’t a surprise, given Eno’s long-standing antipathy to documentaries.

In the 1993 film “Words for the Dying,” which chronicled an album he made with John Cale of the Velvet Underground, Eno growled, “Keep that bloody camera off me,” and flipped off the cameraman.

Eventually, Eno agreed to allow the director, Rob Nilsson, to film only his hands and feet. “Great cat and mouse game,” Nilsson said in an email. “I think Brian made the film more interesting.”

Hustwit, a self-taught filmmaker who worked in music and publishing before turning to documentaries (“Helvetica,” 2007), isn’t the sort to surrender. He’d met Dawes in 2009, when they were on a South by Southwest panel, and over email, they discussed the possibility of making an Eno movie that was never the same twice. “I always want to do things I don’t know how to do,” Dawes said during a video interview from his home in Southport, England.

Hollywood has dallied with nonlinear stories before. When “Clue” played theaters in 1985, viewers randomly saw one of three different endings. Steven Soderbergh’s HBO miniseries “Mosaic” (2017) was accompanied by a mobile app that allowed users to view the drama from the perspectives of different characters, and more recently, Netflix’s “Choose Love” (2023) offered a choose-your-own-adventure component that branched into six possible endings. But Hustwit knew he couldn’t hook Eno with half-measures.

Dawes, who taught himself computer programming in high school, said it took “two years of really intense work” to write the software, Brain One (an anagram for Brian Eno), for the film, he said. Hustwit first used it to create a generative remix of “Rams” and showed it to Eno.

When Eno saw it, he was excited, he said in an email interview. (He even used an exclamation mark!) “I didn’t fancy the linearity of conventional biographies,” he said. “Lives don’t run in straight lines, and every time we think about them in retrospect (i.e., every time we start remembering) we actually rethink them. Our lives are stories we write and rewrite. There is no single reliable narrative of a life.”

On the festival circuit, Hustwit and Dawes occasionally brought the Brain One machine onstage and tweaked “Eno” in real time, adjusting the audio for each theater’s acoustics. When the movie plays Film Forum in New York, they’ll create individual Digital Cinema Packages, which modern projection systems use in lieu of film reels, for each screening.

Ever since Bach wrote “The Art of Fugue” in the 1740s and didn’t specify any tempo or instrumentation, composers have experimented with indeterminacy. In 1958, composer Christian Wolff said that he, Morton Feldman and John Cage, as well as Pierre Boulez, Karlheinz Stockhausen and others, used chance procedures to achieve “a kind of objectivity, almost anonymity,” resulting in music that was “free of artistry and taste.”

Artist-free art remains a niche, though. Siddhant Adlakha reviewed the Sundance premiere of “Eno” for IndieWire and denounced the random elements as “tomfoolery,” while criticizing its “haphazard placement of emotional denouements.”

Nicolai, the German composer, hadn’t seen “Eno,” but shared Adlakha’s aversion to randomness. “I like it when people make clear artistic decisions,” he said. “In a time of so-called AI, personality becomes even more important.” Using technology to randomize content and narrative, he added with a laugh, “becomes a little bit garbage.”

In his email, Eno pointed out that all music was generative before the invention of notation, around the year 1000. And a generative tradition endured until the middle of the 19th century, when the invention of recording allowed people to hear a piece of music over and over in the same static form. “Generative music is actually a return to an earlier way of listening, in which each experience was unique and transient,” he wrote. “I prefer to think that nongenerative music is the niche.”

Maybe the emotional payoff of a fixed narrative is too ingrained in audiences to be eliminated. It certainly hasn’t been easy for Hustwit to adapt “Eno” to the commercial conventions of streaming and DVDs.

“The reaction from the film industry has been curiosity and excitement, but also confusion,” he said. “Everyone wants me to make a director’s cut. I could make a really good one, but that would be sort of antithetical to the whole exercise, for me to exert that level of control.”

Streaming platforms don’t have the ability to generate unique versions of a movie for every viewer, but neither Hustwit nor Dawes has ever been deterred by tradition. Their company, Anamorph, is developing new software that would allow streamers to create versions of “Eno” that change with each viewing. It’s not possible to watch all 52 quintillion versions of the film, but some Eno fans will try.

This article originally appeared in The New York Times.