Musical works created by recording natural sounds and subsequently altering and rearranging them into a composition. The word "concrète" refers to the method of working directly with sound rather than a system of abstract musical notation. Originally recorded onto discs, these works were later realized with magnetic tape as the technology became available. Developed by the French composer Pierre Schaeffer and colleagues, including Pierre Henry, in the Club d'Essai and Groupe de Recherches Musicales at the Office de Radio-diffusion et Télévision Française ca. 1948. The term "musique concrète" is reserved for works created solely with naturally occurring sounds recorded onto disc or magnetic tape. For works created from sounds generated primarily by electronic synthesis, or using combinations of natural and synthesized sound, use "electronic music."

Source: Art & Architecture Thesaurus

http://vocab.getty.edu/page/aat/300266052