aleatory music
English composer
Definition
Music in which some element of the composition or performance is left to chance or the performer's choice. Boulez distinguished carefully between chance operations (which he rejected) and controlled indeterminacy — providing performers with clearly defined options whose unpredictable combination creates a mobile formal structure.
Interpretive Guidance
In Boulez's piano works, aleatory elements are always constrained: the Third Sonata offers choices of ordering, not of notes. The performer's freedom is architectural, not improvisatory. Approach each decision as a structural argument, not a spontaneous gesture.