aleatory

The use of random or chance elements in certain art forms. Although Leonardo da Vinci recommended looking at blotches on walls as a means of initiating artistic ideas, aleatory practice has been mainly employed by 20th-century avant-garde artists.

In Dada, artist Hans Arp made collages by dropping small pieces of paper onto a larger piece and fixing them where they landed. Similarly, his colleague Tristan Tzara created poetry by drawing sentences, extracted from newspapers, from out of a hat. In music, the major exponent has been John Cage, who pioneered a method of composition in which the elements are assembled by using dice or a computer.