Originally published by Pastelegram.

On the evening of March 5, 1968, John Cage sat down to play a game of chess with Marcel Duchamp. A bottle of wine sat on the table between them. Duchamp smoked a cigar, Cage a cigarette. Duchamp’s wife Teeny sat next to her husband observing the game. There was a small hole in the center of each square on the chessboard, and a tangle of cables ran from the side of the board to a stack of small boxes on the floor. A bright spotlight poured down on the players, while an audience of several hundred looked on from their seats in the theater.

As the gameplay commenced, sounds emanated from eight speakers placed evenly around the theater. The holes in the chessboard contained photoresistors, which controlled the flow of music from “sound-generating systems” prepared and operated by four composers (David Behrman, Lowell Cross, Gordon Mumma and David Tudor). Each composer could send up to four channels of audio into the mixer. Depending on the arrangement of pieces on the board (i.e. the amount of light received by each of the sixty-four photoresistors), these sixteen channels variously turned on or off, and moved from speaker to speaker. Lowell Cross, who designed and built the chessboard, later wrote that his arrangement of the circuits “was arbitrary, unplanned and quasi-random, but any of the sixteen inputs had a ‘chance’ of appearing in as many as four of the eight loudspeaker locations surrounding the audience.”

Cross, with some general guidance from Cage, had created an algorithm for mixing music according to sixty-four variables, though their values had nothing to do with music. More importantly, he had created a system for turning a chess game into a concert, a quotidian exercise into high theater. These themes come up throughout Cage’s career. Starting in the 1940s, he used the I Ching (an ancient Chinese divination system containing sixty-four hexagrams) to produce Music of Changes and other works. In the 80s he enlisted composer and programmer Andrew Culver to write a DOS program replicating the chance operations of the I Ching. The parameters of this program indicate a sophisticated understanding of chance on Cage’s part; the user can introduce varying degrees of “fixed bias” and “movable bias” into the algorithm to constrain the randomization.

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