Acousmatic music in the context of "Sound effects"

Musique concrète (French pronunciation: [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 (French: 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 (French: musique acousmatique) was used in reference to fixed media compositions that utilized both musique concrète-based techniques and live sound spatialisation.

Acousmatic sound is sound that is heard without an originating cause being seen. The word acousmatic, from the French acousmatique, is derived from the Greek word akousmatikoi (ἀκουσματικοί), which referred to probationary pupils of the philosopher Pythagoras who were required to sit in absolute silence while they listened to him deliver his lecture from behind a veil or screen to make them better concentrate on his teachings. The term acousmatique was first used by the French composer and pioneer of musique concrète Pierre Schaeffer. In acousmatic art one hears sound from behind a "veil" of loudspeakers, the source cause remaining unseen. More generally, any sound, whether it is natural or manipulated, may be described as acousmatic if the cause of the sound remains unseen. The term has also been used by the French writer and composer Michel Chion in reference to the use of off-screen sound in film. More recently, in the article Space-form and the acousmatic image (2007), composer and academic Denis Smalley has expanded on some of Schaeffers' acousmatic concepts.Since the 2000s, the term acousmatic has been used, notably in North America to refer to fixed media composition and pieces.

Pierre Henri Marie Schaeffer (English pronunciation: /piːˈɛər ˈhɛnriː məˈriː ˈʃeɪfər/ , French pronunciation: [ʃɛfɛʁ]; 14 August 1910 – 19 August 1995) was a French composer, writer, broadcaster, engineer, musicologist, acoustician and founder of Groupe de Recherche de Musique Concrète (GRMC). His innovative work in both the sciences—particularly communications and acoustics—and the various arts of music, literature and radio presentation after the end of World War II, as well as his anti-nuclear activism and cultural criticism garnered him widespread recognition in his lifetime.

Schaeffer is most widely and currently recognized for his accomplishments in electronic and experimental music, at the core of which stands his role as the chief developer of a unique and early form of avant-garde music known as musique concrète. The genre emerged in Europe from the utilization of new music technology developed in the post-war era, following the advance of electroacoustic and acousmatic music.