Ever Heard of Chance Music?

aleatory music (ā'lēətфr'ē) [Lat. alea=dice game], music in which elements traditionally determined by the composer are determined either by a process of random selection chosen by the composer or by the exercise of choice by the performer(s). At the compositional stage, pitches, durations, dynamics, and so forth are made functions of playing card drawings, dice throwings, or mathematical laws of chance, the latter with the possible aid of a computer. Those elements usually left to the performers' discretion include the order of execution of sections of a work, the possible exclusion of such sections, and subjective interpretation of temporal and spatial pitch relations. Also called “chance music,” aleatory music has been produced in abundance since 1945 by several composers, the most notable being John Cage, Pierre Boulez, and Iannis Xenakis.

Aleatoric (or aleatory) music or composition, is music where some element of the composition is left to chance. The term became known to European composers through the lectures which acoustician Werner Meyer-Eppler held at Darmstadt Summer School in the beginning of the fifties. According to his definition, "aleatoric processes are such processes which have been fixed in their outline but the details of which are left to chance".

The word alea means "dice" in Latin, and the term has become known as referring to a chance element being applied to a limited number of possibilities, a method employed by European composers who felt more bound than the Americans by tradition and who stressed the importance of compositional control, as opposed to indeterminacy and chance where possibilities tend not to be finite and which is an Anglo-Saxon phenomenon.

The term was used by the French composer Pierre Boulez to describe works where the performer was given certain liberties with regard to the order and repetition of parts of a musical work. The term was intended by Boulez to distinguish his work from works composed through the application of chance operations by John Cage and his aesthetic of indeterminacy - see indeterminate music. Other examples of aleatoric music are Klavierstьck XI by Stockhausen which features a number of elements to be performed in changing sequences and characteristic sequences to