Piano Phase

It is one of his first attempts at applying his "phasing" technique, which he had previously used in the tape pieces It's Gonna Rain (1965) and Come Out (1966), to live performance.

Reich had earlier used tape loops in It's Gonna Rain (1965) and Come Out (1966), but wanted to apply the technique to live performance.

[1] Reich carried out a hybrid test with Reed Phase (1966), combining an instrument (a soprano saxophone) and a magnetic tape.

[2] The first performance of the version for four pianos was given on March 17, 1967 at the Park Place Gallery, with Art Murphy, James Tenney, Philip Corner, and Reich himself.

Reich called the unexpected ways change occurred via the process "by-products", formed by the superimposition of patterns.

The superimpositions form sub-melodies, often spontaneously due to echo, resonance, dynamics, and tempo, and the general perception of the listener.

[6] According to musicologist Keith Potter, Piano Phase led to several breakthroughs that would mark Reich's future compositions.

The first is the discovery of using simple but flexible harmonic material, which produces remarkable musical results when phasing occurs.

In 2004, a college student named Rob Kovacs gave the first solo performance of the piece at the Baldwin Wallace Conservatory of Music.

On January 28, 2013, the soloists of the Theatre of New Music ensemble Vasily Igonin and Alexey Popov performed this work for the first time in Saratov in the Small Hall of the Conservatory, and on April 25 they repeated the performance of this work at the concert "The Edges of Modernity" in the Great Hall of the Saratov Conservatory.