Music for Mallet Instruments, Voices and Organ

Music for Mallet Instruments, Voices and Organ is a 1973 composition by American composer Steve Reich. The piece is scored for glockenspiels, marimbas, metallophone (vibraphone without resonator fans), women's voices, and organ, and runs about 17 minutes.

The piece is in four sections, played without a break, marked off by changes in key and meter:
F Dorian in 34
A♭ Dorian in 24
B♭ minor in 34
D♭ in 34.

The piece features two interrelated musical processes: the building up of a duplicate of a preexisting pattern played by the marimbas and the glockenspiels, and the augmenting (lengthening of the duration of notes) of repeated chord cadences of the women's voices and organ. The women's voices sing a simple vowel sound, ee, doubling upper notes of chords played by the organ.