DAVIS:

As a teenager, Mabry went to New York City to study at the Fashion Institute of Technology; she brought along a notebook full of songs. She worked as a model for the Wilhelmina agency, appearing in Glamour and Seventeen magazines and as a pinup in Jet magazine. She also worked as a club hostess, and she savored the city's 1960s nightlife and met figures such as Andy Warhol and Jimi Hendrix.

Her first single, in 1964, was "The Cellar." According to Danielle Maggio, an ethnomusicologist and adjunct professor at the University of Pittsburgh who wrote her dissertation on Ms. Davis, the song was named after a private club at Broadway and West 90th Street. Ms. Davis became its master of ceremonies, disc jockey, and hostess, and the club drew artists, musicians, and athletes.

In 1967, the Chambers Brothers recorded one of her songs, "Uptown." South African trumpeter Hugh Masekela, then her boyfriend, produced a 1968 single for her, "Live, Love, Learn."

She met Miles Davis at a jazz club and became his second wife in 1968. A photograph of her is the cover of Davis's 1969 album, "Filles de Kilimanjaro," which includes a tune titled "Mademoiselle Mabry." Ms. Davis introduced her husband to the music of Hendrix and Sly Stone, catalyzing his move into rock and funk.

While Davis was working on a later album, he considered calling it "Witches Brew"; his wife suggested "Bitches Brew," the title that stuck. She also persuaded him to trade the dapper suits of his previous career for flashier contemporary fashion. "I filled the trash with his suits," she recalled in the film.

Davis encouraged her to perform. In 1969, he produced sessions for her, choosing musicians including Herbie Hancock and Wayne Shorter from Davis's quintet and Mitch Mitchell and Billy Cox from Hendrix's Band of Gypsys. His label, Columbia Records, rejected the results, which remained unreleased until 2016.

The marriage was turbulent and sometimes violent before ending in 1969. "Miles was pure energy, sometimes light but also dark," Betty Davis recalled in the film. "Every day married to him was a day I earned the name Davis."

She kept the name as she returned to songwriting. Material she wrote for the Commodores brought her an offer to record for Motown, but she turned it down because she insisted on keeping her publishing rights.

Ms. Davis subsequently moved to London -- where a new boyfriend, Eric Clapton, offered to produce an album for her... 

Tweet   @brothersjudd