a musical composition in which some elements of the composition are left to chance , and/or some primary elements of the realization of a composition are left to the determination of its performer or performers a. open form c.textural composition b.musique concrete
"Open form" is traditionally referred to as "aleatoric music": a score is provided but the composer has left some choices open. The term "aleatoric" music implies that chance determines how to fill the open spaces.
