Steve Reich's Piano Phase
Governed by mathmematical patterns, phasing produces some rhythmically complex pieces.
One of the compositional techniques most associated with Steve Reich is the process of phasing music.
In his experiments with compositional techniques, Steve Reich (1936--) developed the concept of phasing music. His first work to use phasing in live performance (Reich had already experimented with phasing in mixed tape loops) was "Piano Phase," and this piece illustrates the rhythmic complexity of phasing.
The technique involves the play of a constant against a variable element, moving cyclically from unity to tension and returning to unity. In a phased piece of music, one instrument plays a single line repeatedly as the constant in the piece.
A second instrument starts out playing in unison with the constant line and gradually increases speed until the two lines sound out of synch. The second line gradually increases speed again until the two lines are once more playing in unison. The whole process is very similar to what happens when a fast runner races next to a slow runner on a circular track. The two runners start together at the signaling gunshot, but the fast runner soon leaves the slow runner behind.
However, the fast runner will eventually catch up to the slow runner, and the two will be running next to each other once more. The slow runner acts as a constant while the fast runner moves in and out of synchronization (this is not to say that the constant instrument never gets to vary other elements such as the notes in its line; rather the constant remains for the most part unchanged in its rate of speed).
In "Piano Phase," the two piano players begin with a 12-note melodic fragment repeated several times. Then Player No. 2 speeds up his line until his second note is in synch with the first note of Player No. 1 (see the figure below). Then Player No. 2 speeds up again until his third note sounds at the same time as the first note of Player No. 1.
He continues increasing speed till he has cycled through all 12 notes. The melody then changes to an 8-note pattern and the process is repeated. A 4-note pattern completes the set of cycles, and the two players end the piece in unison.
For more information on Steve Reich and his work, please visit the following websites:
