From Wikipedia...

Jack Johnson, also known as A Tribute to Jack Johnson, is a soundtrack recorded by American jazz musician Miles Davis. The album was the second film score Davis had composed, after Ascenseur pour l'échafaud in 1957.[4] In 1970, Davis was asked by Bill Cayton to record music for his documentary of the same name on the life of boxer Jack Johnson.[5] Johnson's saga resonated personally with Davis, who wrote in the album's liner notes of Johnson's mastery as a boxer, his affinity for fast cars, jazz, clothes, and beautiful women, his unreconstructed blackness, and his threatening image to White men.[6]
Jack Johnson was a turning point in Davis' career and has since been viewed as one of his greatest works. Davis, who wanted to put together what he called "the greatest rock and roll band you have ever heard,"[8] recorded with a line-up featuring guitarists John McLaughlin and Sonny Sharrock, keyboardists Herbie Hancock and Chick Corea, clarinetist Bennie Maupin, and drummers Jack DeJohnette and Billy Cobham.[7] The album's two tracks were drawn from one recording session on April 7 and edited together with recordings from February 1970 by producer Teo Macero. The music reflected Davis' interest in the eclectic jazz fusion of the time, but also foreshadowed the hard-edged funk that would fascinate him in the next few years.