Musique concrète (French: [myzik kɔ̃kʁɛt]; lit. 'concrete music') is a type of music composition that utilizes recorded sounds as raw material. Sounds are often modified through the application of audio signal processing and tape music techniques, and may be assembled into a form of sound collage. It can feature sounds derived from recordings of musical instruments, the human voice, and the natural environment as well as those created using sound synthesis and computer-based digital signal processing. Compositions in this idiom are not restricted to the normal musical rules of melody, harmony, rhythm, and metre. The technique exploits acousmatic sound, such that sound identities can often be intentionally obscured or appear unconnected to their source cause. The theoretical basis of musique concrète as a compositional practice was developed by French composer Pierre Schaeffer beginning in the early 1940s. It was largely an attempt to differentiate between music based on the abstract medium of notation and that created using so-called sound objects (l'objet sonore). By the early 1950s musique concrète was contrasted with "pure" elektronische Musik as then developed in West Germany – based solely on the use of electronically produced sounds rather than recorded sounds – but the distinction has since been blurred such that the term "electronic music" covers both meanings. Schaeffer's work resulted in the establishment of France's Groupe de Recherches de Musique Concrète (GRMC), which attracted important figures including Pierre Henry, Luc Ferrari, Pierre Boulez, Karlheinz Stockhausen, Edgard Varèse, and Iannis Xenakis. From the late 1960s onward, and particularly in France, the term acousmatic music (musique acousmatique) was used in reference to fixed media compositions that utilized both musique concrète-based techniques and live sound spatialisation. Source: Wikipedia (en)