For a few short years in the 1970s, no one made funk as raw as Betty Davis did. She sang bluntly about sex on her own terms, demanding satisfaction with feral yowls and rasps, her voice slicing across the grooves that she wrote and honed as her own bandleader and producer. Her stage clothes were shiny, skimpy, futuristic fantasies; her Afro was formidable.
A major label, Island, geared up a big national push for her third album, “Nasty Gal,” in 1975. But mainstream radio didn’t embrace her, and Island rejected her follow-up recordings. Not long afterward, she completely dropped out of public view for decades.
Ms. Davis’s voice now — speaking, not singing — resurfaces in “Betty: They Say I’m Different,” an impressionistic documentary that will have its United States theatrical premiere on Wednesday at the Billie Holiday Theater in Bedford-Stuyvesant, Brooklyn, as part of the Red Bull Music Festival. The film includes glimpses of virtually the only known concert footage of Ms. Davis in her lascivious, head-turning prime, performing at a 1976 French rock festival. The present-day Ms. Davis is shown mostly from behind and heard in voice-over, though there is one poignant close-up of her face.
This month Ms. Davis, 72, gave a rare interview by telephone from her home near Pittsburgh to talk about the film and her music. After years of entreaties from and conversations with its director, Phil Cox, and producer, Damon Smith, she agreed to cooperate on “Betty: They Say I’m Different” because, she said, “I figured it would be better to have them cover me when I was alive than when I was dead.”
Mr. Cox said, via Skype from England, “Betty doesn’t want sympathy, and she’s found her own space now. To me, that is just as interesting as that woman she was in the 1970s. It’s the antithesis of the age we live in, where everybody wants to be on social media all the time.”
Ms. Davis has longtime fans from the ’70s and newer ones who have discovered her in reissues and through hip-hop samples. They have clung to a catalog and a persona that were musically bold, verbally shocking and entirely self-created. Long before the current era of explicit lyrics, Ms. Davis was cackling through songs like “Nasty Gal” — “You said I love you every way but your way/And my way was too dirty for you” — and “He Was a Big Freak,” which boasts, “I used to whip him/I used to beat him/Oh, he used to dig it.” She still won’t reveal who was, or whether there was, a real-life model for songs like those.
“I wrote about love, really, and all the levels of love,” she said. That emphatically included sexuality. “When I was writing about it, nobody was writing about it. But now everybody’s writing about it. It’s like a cliché.”
Ms. Davis was born Betty Mabry in Durham, North Carolina, in 1945, and she grew up there and in Pittsburgh. She headed to New York City in the early 1960s, when she was 17, and enrolled at the Fashion Institute of Technology. She supported herself as a model and a club manager; she reveled in the city’s night life, meeting figures like Andy Warhol, Sly Stone, Eric Clapton and Jimi Hendrix.
She had been writing songs since she was 12, and she got a chance to record some independent soul singles in the mid-1960s. In 1967, the Chambers Brothers recorded one of her songs, “Uptown to Harlem,” which vows, “If the taxi won’t take me I’ll take a train,” and in 1968, her then-boyfriend Hugh Masekela arranged a single for her, “Live, Love, Learn,” that she now dismisses as “so mushy.”
She caught the eye of Miles Davis, who had already caught hers. “I saw this great-looking man at this dance concert,” she said. After she found out who he was, she went to hear him perform at the Village Gate. Mr. Davis spotted her and sent over his bodyguard to tell her, she recalled, that the trumpeter would “like to have a drink with you.”
They were married in 1968 and divorced after a turbulent, sometimes violent year. “Every day married to him was a day I earned the name Davis,” she says in the film. Her face is on the cover of “Filles de Kilimanjaro,” an album Mr. Davis recorded in 1968. He produced recording sessions for his wife in 1969 with his musicians — including Herbie Hancock, Wayne Shorter and John McLaughlin — along with Jimi Hendrix’s rhythm section, Billy Cox and Mitch Mitchell. Shelved by Columbia Records, the sessions were released in 2016 as “The Columbia Years: 1968-69.”
One of the songs she recorded was Cream’s “Politician,” but, Ms. Davis said, “That song made him so uptight, because it was so suggestive for his wife to say ‘Get into the back seat.’” It led, Ms. Davis said, to a song title Miles Davis would release years later: “Back Seat Betty.”
After the divorce, Ms. Davis forged her own music career. She had written a trove of songs; she knew top musicians. “I never considered myself a great singer,” Ms. Davis said. “I think Chaka and Aretha are great singers. But I could connect with the ambience of a song. I could project my feelings and my words to the music.”
Michael Lang, a promoter of the 1969 Woodstock festival, signed her to his label, Just Sunshine, and Greg Errico, the drummer from Sly and the Family Stone, produced her 1973 debut album, “Betty Davis,” backing her with San Francisco luminaries. To tour, Ms. Davis assembled a band named Funk House.
Encouraged by Miles Davis, who told her she had all the skills she needed, she produced her next two albums herself. She sang each line of the arrangements. “Betty would get the ideas for the music, and she would put it on tape. She’d be humming on the cassette, and we’d learn all the parts,” said Fred Mills, the guitarist in the final lineup of Funk House, in a telephone interview. “She had it in her head all the time. And she would always be, like, ‘You got to get rough!’ Lord have mercy, she was killing me.” He chuckled.
There was never any question, Ms. Davis said, that she was in charge. “I never got any woman-man situations going on with the music,” she said. “Everyone was very cooperative. The music that I made, I never had any problem with the musicians.”
Ms. Davis saw herself following through on the blues and rock ’n’ roll she had grown up on in the 1950s. Her song “They Say I’m Different” name-checks Big Mama Thornton, Howlin’ Wolf and Chuck Berry as role models. But she was well aware that her performances drew strong reactions. “I used to make the guys uptight sometimes,” she said. “The women were very receptive with me.”
Was she making a feminist statement? “How could I think about feminism with the songs I was writing?” she said, and laughed. “I never thought women had power. We had power in the bedroom, but we didn’t have political power.”
In 1975, “Nasty Gal” was to be her make-or-break moment. Along with her most jaggedly assertive funk, it also included “You and I,” a ballad written with Miles Davis and arranged by Gil Evans. But the album was too radical for its era. Ms. Davis and Funk House recorded what was to be a follow-up album, including the bitter “Stars Starve, You Know,” but Island did not release it and dropped her contract.
“When I was told that it was over, I just accepted it,” she said. “And nobody else was knocking at my door.”
After the death of her father in 1980, “I went to another level,” she said. “It was no longer about the music or anything, it was about me losing a part of myself. It was devastating.”
There was one more flicker in her performing career. In the early 1980s, she said, she spent a year in Japan, where she played club dates with a Japanese band. The film reveals that in a visit to Mount Fuji, where she met silent monks, she found a spiritual revelation. After her time in Japan, she said, “I just got very quiet.”
Mr. Cox said, “She had a battle with inner demons and a desire for solitude. I think she was just exhausted as well.”
But her music was not forgotten. In the 2000s, persistent longtime fans convinced her to allow reissues of her recordings on the dedicated archival label Light in the Attic. It has released all three of her 1970s albums, as well as her Columbia sessions from the 1960s and her last ’70s sessions with Funk House.
Belatedly, she has been acknowledged as an influence and inspiration for generations of musicians, from Prince and Rick James to Erykah Badu and Janelle Monáe. Yet even with her music restored and her story being told, Ms. Davis has ruled out performing again. “With age, your looks change,” said Ms. Davis, who prefers not to disturb her fans’ image of her. “I want to leave them with what they had,” she said.