“Four Organs” is the ultimate minimalist composition. Performed by Reich, Glass, Art Murphy and Steve Chambers, four identical Farfisa organs strike a single chord and gradually lengthen each note to produce polyrhythms between the players. Anchored by Jon Gibson’s stoically-steady pulse on maracas, the piece deconstructs its opening burst to a sustained mass of sound – stretching the tones to create (in Reich’s words) “slow-motion music.” Inspired by Reich’s early training on drums, “Phase Patterns” treats the keyboards like tuned percussion instruments: a basic rhythm pattern is played in unison and almost imperceptibly increases tempo to move out-of-sync. Each progressive cycle emphasizes unique figures that are not generated by an individual alone, but rather emerge from the communal expression of the group. Originally released on Shandar in 1971, Four Organs / Phase Patterns is one of the most highly regarded avant-garde recordings of the past 50 years.