The first major recording session for the album, which took place on April 7, 1970, was almost accidental: John McLaughlin, awaiting Miles’s arrival, began improvising riffs on his guitar, and was shortly joined by Michael Henderson and Billy Cobham. Meanwhile, the producers brought in Herbie Hancock, who had been passing through the building on unrelated business, to play the Farfisa organ. Miles arrived at last and began his solo at about 2:19 on the first track. The album’s two long tracks were assembled in the editing room by producer Teo Macero. “Right Off” is constructed from several takes and a solo by Davis recorded in November 1969. It contains a riff from Sly and the Family Stone’s “Sing a Simple Song”. Much of the track “Yesternow” is built around a slightly modified version of the bassline from the James Brown song “Say It Loud – I’m Black and I’m Proud”; this may be a deliberate allusion to the song’s Black Power theme as it relates to the film’s subject. “Yesternow” also incorporates a brief excerpt of “Shhh/Peaceful” from Davis’s 1969 album In a Silent Way and a 10-minute section comprising several takes of the tune “Willie Nelson” from a session on 18 February 1970.