of musical measures, for which each measure had several possible versions and a procedure for selecting the precise sequence based on the throwing of a number of dice.

The French artist Marcel Duchamp composed two pieces between 1913 and 1915 based on chance operations. One of these, Erratum Musical, written with Duchamp's sisters Yvonne and Magdeleine for three voices, was first performed at the Manifestation of Dada on 27 March 1920, and was eventually