“Satan & Adam” chronicles a famous odd-couple blues duo who made their name on the streets of Harlem, earned fame by appearing on a U2 concert album and found a little success and a little heartache in the years that followed.

“Twenty years in the making,” as the hype goes, editor-turned director/editor V. Scott Balcerek caught guitar virtuoso “Mister Satan” and his harmonica-playing “apprentice” Adam Gussow in the ’80s, shortly after they teamed up.

And he didn’t lose touch over the decades, filming them in black and white back then, in color in later years and today. He’s assembled that footage, with interviews, eyewitness testimonials and the like into a charming and engaging history of a pop cultural phenomenon.

In 1986, Gussow was a Princeton grad and grad student at Columbia, fresh off a romantic breakup, “which put me in a space where I could be…struck by the blues.”

In Harlem, about a block north of the famed Apollo Theater, a “One Man Blues Band” ripping it up on a guitar, keeping time with tambourine and high hat via pedals, Mister Satan did the striking.

Passionate, accomplished, a beloved local landmark and just a little off — as anybody who bills himself “Mister Satan” is likely to be — the guitarist let the kid sit in with him for a couple of tunes, playing harmonica.

“I won’t embarrass you,” Gussow promised. He didn’t.

As word spread, “Satan’s gonna play with the WHITE boy,” a crowd gathered. And as the electric shock of that first collaboration settled in, an act was born — “Satan & Adam.”

The novelty of seeing them caught on with passersby, and then won the attention of the New York media. And as it did, Gussow learned of Mister Satan’s previous life.

He’d been on Ray Charles’ record label, had a minor hit (“Oh She was Pretty”).

As Sterling Magee, the singer-guitarist played with Etta James, Little Anthony and the Imperials and Marvin Gaye. He’d backed up James Brown at the Apollo just down the street from their regular spot. Now, he was playing on the street. That moniker he was now going by explained a lot.

He billed himself as Mister Satan, “the Prince of Darkness,” because “I can go into the darkness of my mind and come out with beautiful things.”

Yeah, he’s a bit of a free thinker. He is “from the same planet as George Clinton, Sun Ra” record producer Rachel Faro opines. And as they played together, were suddenly “discovered” by U2 as they and director Phil Joanou made “Rattle & Hum” (Joanou and The Edge are among those interviewed), landed first a regular club gig, then an agent, then a record deal and tours here and abroad, Gussow figured out what’s pretty obvious the moment we see Satan on the screen.

He’s a flake, a great musician who could accept this “success” only up to a point, function normally only within his own parameters based on hard life experience and a touch of mental illness.

“Satan & Adam” has Gussow do most of the narrating, and what we pick up from him is how this educated New Yorker, obsessed with the blue and Southern Black culture, made his peace with that.

The payoff? They became almost famous, opening for Buddy Guy in Central Park, touring Europe as the opening act for Bo Diddley,

Magee relates his Mississippi childhood, raised on Gospel, falling into “serving the Devil, playing the blues.”

“I don’t do it for money,” he is heard saying. “I don’t do it for fame.”

Gussow got a taste of both of those with Magee, marveling at how when they were busking on the street, they’d split the bills, but Mister Satan would “blow up” if he didn’t get all the change. He always gave the coins away to the local homeless.

And “fame” was never going to sit well with the guitar man.

The college grad never quite got over his awe. “I was his boy, not his equal. His apprentice. I knew this was the best gig I was ever going to have.”

All he had to do was keep Satan’s equally “off” wife from wrecking the act while they were on the road, keep Satan on task when they had steady gigs (The Magees moved to Virginia after a dispute with a New York landlord) and talk him into the recording studio.

Rev. Al Sharpton and journalist Peter Noel provide cultural context, what else was happening as these two became celebrated. The New York of the “Do the Right Thing” era, when the gap between the haves-and-have-nots was widening and racial tensions were spiking was a tricky place to launch a salt-and-pepper act.

“Suddenly, I was the problem,” Gussow remembers, “just one more white man come to rip off the black man’s music.”

“Cultural appropriation” is addressed more than once, here. But Gussow’s picking up the harmonica and mastering it? Mostly skipped over.

Balcerek’s film makes for a brisk journey through their rise and eventual breakup, generously sampling the duo’s live performances and rendering an interesting if superficial portrait of each man, especially during their rise.

It can feel superficial and less revealing than we might want. Much is left out, but for that we can probably turn to the book got out of the experience. “Mister Satan’s Apprentice.”

MPAA Rating: unrated, profanity

Cast: Sterling Magee, Adam Gussow, The Edge, Harry Shearer, Rachel Faro

Credits:Directed by V. Scott Balcerek, script by V. Scott Balcerek, Ryan Suffern. A Cargo release.

Running time: 1:23