Music for a Large Ensemble is a piece of music written by Steve Reich in 1978. It is scored for string instruments, flutes, clarinets, saxophones, trumpets, pianos, marimbas, vibraphones, xylophones and two female voices.

It had its first performance in Utrecht on June 14, 1979. It was a commissioned work by the Holland Festival and it was first performed by Reich's musicians as well as members of the Netherlands Wind Ensemble . Reich noted that this piece was developed out of two pieces he had previously written, Music For Mallet Instruments, Voices and Organ and Music for 18 Musicians. The piece was written for more musicians than Reich had previously worked with, and included instruments from all sections of the orchestra, including strings, woodwinds, brass and percussion, and women's voices. The piece is divided into five sections, each marked by a key change initiated by the metallophone.

As in some of his other works from the same time, Reich uses the technique of augmentation here whereby short, rapid phrases are stretched out to become longer lines, which combine contrapuntally with other melodies, then using diminution they are returned to their shorter length. It is in an "arch" structure, ABCBA, characteristic of Reich's work at this time.

Although the piece is not one of Reich's most popular, it has been recorded several times, most recently in a performance conducted by Alan Pierson .