Chance music, also known as aleatoric music, is a style of composition where some elements of the music are left to chance or indeterminate factors. This can include the use of cards, dice, computer generators, mathematical formulas, the I-Ching, or other methods to make musical decisions. The term "aleatory" comes from the Latin word "alea," meaning "dice," and is often associated with procedures that involve a relatively limited number of possibilities.
There are three main types of chance music:
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Random procedures to produce a determinate, fixed score: In this type, the composition is created using random processes, but the resulting score is fixed and determinate. An example of this is a famous music piece attributed to Wolfgang Amadeus Mozart, which used a musical dice game.
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Mobile form: Mobile form refers to compositions where the structure of the piece can be arranged by the performers, such as reordering sections or playing sections simultaneously as they wish.
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Indeterminate notation: Indeterminate notation includes graphic notation and texts, where performers are instructed to play music based on a drawing or text, rather than a traditional music score.
Some composers and musicians associated with chance music include Karlheinz Stockhausen, John Cage, Luigi Nono, Luciano Berio, and Lukas Foss.
