The exact time and place that the blues was conceived at the close of the 19thcentury remains shrouded in mystery. But there’s no doubt that the quintessential Black American musical form reached a critical creative mass on the south side of Chicago in the late 1950s.Riding the wave of the Great Migration out of the Mississippi Delta, artists such as Howlin’ Wolf, Muddy Waters and Buddy Guy settled in the Windy City, where they plugged in and transformed the country blues into a scorching urban soundtrack.

In his new documentary “Born in Chicago,” San Francisco filmmaker Bob Sarles distills the story of the music’s transmission from these Southern-born innovators to a younger generation of white musicians drawn to the music’s incendiary emotional power.The 77-minute film, which makesits San Francisco debut Sunday, June 5,at the Roxie Theateras part of SF IndieFest’s21stSan Francisco Documentary Film Festival, focuses on the crucial years in the mid-1960s when white musicians like Paul Butterfield, Barry Goldberg, Elvin Bishop, Nick Gravenites and Mike Bloomfield came into their own. (It is alsoavailable onlineas part of the festival’s virtual component.)

“I’m aware that this is a touchy subject these days, what some people call cultural appropriation,” said Sarles, whose 2013 documentary on Bloomfield, “Sweet Blues,” supplied a wealth of relevant interviews with key figures no longer with us, like guitarist Hubert Sumlin and Chess Records co-founder Phil Chess. “ ‘Appropriation’ implies a theft and no payback. I would say this is the opposite. This was a gift, literally Wolf and Mud showing these kids how you play it. And as soon as they got any traction, they turned around and opened doors for their mentors.”

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With pitch-perfect narration by Dan Aykroyd, the film follows the music’s path to San Francisco, where the integrated Paul Butterfield Blues Band injected a bracing dose of Chicago grit into the emerging acid- rock scene. Powered by Howlin’ Wolf’s rhythm section of drummer Sam Lay and bassist Jerome Arnold, Butterfield and his live-wire guitar tandem of Bloomfield and Bishop reconfigured the Bay Area’s musical landscape.

“You can’t imagine the impact that the Butterfield Blues Band had on the San Francisco music scene in March 1966 unless you were there,” said former Chronicle music writer Joel Selvin, who co-produced and wrote the screenplay for “Born in Chicago.” He caught Butterfield at UC Berkeley’s Harmon Gym in the spring of ’66, and watched as “it set all sorts of things in motion. By the time they play Monterey Pop in ’67, it’s starting to coast downhill. The cultural and social impact peaked.”

一个关键whi开发启动te musicians introduced the Black blues giants of Chicago to wider audiences. Bloomfield had already helped spark a musical revolution with Bob Dylan’s epochal plugged-in performance at the 1965 Newport Folk Festival. He then becomes musical consigliere to budding impresario Bill Graham, “and suddenly you see Big Mama Thornton, Howlin’ Wolf, Buddy Guy, and these older Black musicians at the Fillmore,” Sarles said.

“Born in Chicago” doesn’t ignore the wave of working-class blokes marshaling their blues fanboy forces for the British Invasion. Keith Richards makes a requisite appearance. But the story here is a deeply American tale that highlights the particular racial and generational dynamics at work. At a time when rising R&B and soul stars like James Brown, Jackie Wilson and Sam Cooke served as beacons for young Black musicians, the older Southern-raised blues artists embraced the white teenagers obsessed with their music. “For some reason, young Blacks didn’t like the word ‘blues,’” B.B. King says in an interview.

Part of what makes “Born in Chicago” so satisfying is that Sarles lets the music breathe. Tapping into a wealth of archival footage, he matches every assertion about a musician’s power with several clips that make the case with sweaty authority. Sarles and his wife, co-producer and story editor Christina Keating,are masters of concision,havinglearned to distill the essentials of a story by making dozens of short, career-encapsulating films for the Rock & Roll Hall of Fame, VH1 and various museums.

但是考虑到项目的不寻常的起源,”诞生了in Chicago” is truly an underdog triumph. Originally directed by John Anderson (co-credited with Sarles as director),the docwas first released in 2013 in an incarnation that centered on Goldberg, Gravenites, Harvey Mandel and Corky Siegel’s Chicago Blues Reunion Band.

The film was fairly well received, but the original producers weren’t satisfied. They approached Sarles, who said he would tackle the project if he could build on its foundation. “It had good bones and good potential,” said Sarles, who noted that he is still looking for North American distribution. “It evolved from a quasi-concert documentary with interstitial interviews.”

For overall vision, Sarles turned to Selvin, with whom he’d collaborated closely on “Bang! The Bert Berns Story,” a 2016 documentary based on Selvin’s biography of the prolific but short-lived songwriter and producer. Remarkably, the seams between the twoversions of“Chicago” are mostly invisible. Interviewing only people who were present and have something important to say,Sarles and Selvintell one specific chapter in a much larger musical saga.

“You can never be comprehensive,” Sarles said. “If you try, you’re going to fall on your face because of what you didn’t put in there.”

“Born in Chicago”:In person or online, 8:45 p.m. Sunday, June 5. $15. Roxie Theater, 3117 16th St., S.F.415-863-1087.sfdocfest2022.eventive.org.