I hear acid jazz growing out of fusion circa Bitches Brew, and reaching a local maximum in 1975 with the release of Miles' two double live albums Pangaea and Agharta, recorded 1 February 1975 at the Osaka Festival Hall.

Miles had been jamming with Jimi Hendrix, intending to record together. Jimi's early departure put the kibosh on that, but Miles was very interested in the distortion and feedback tones and timbres that he heard from Hendrix, and shortly set out to form "the hardest rock'n'roll band in America," as he put it. To play the sounds he was hearing Miles enlisted Pete Cosey to play lead guitar and guitar synth, Reggie Lucas on rhythm guitar, Michael Henderson on bass, Sonny Fortune on saxophones, Al Foster on drums and James "Mtume" Forman on percussion. Miles himself played trumpet of course, but also organ, cranked up to distort and then fed through a wah pedal.

I've never heard the day/night contrast some speak of in the two Osaka performances on Agharta and Pangaea (same day, matinee and evening). To me they both sound primordial: rumbling, driving heavy bottom with incredibly funky guitar from Reggie Lucas, and Pete Cosey's screeching, whispering, wailing leads soaring above it all. The two sets take the listener on the proverbial trip; Africa-tinged, with dynamics from loud to soft and hard to lyrical, but always swinging in straight-ahead 4/4 time.

You've never heard anything like it.