In 1966, Pierre Schaeffer proposed the term acousmatic to define 'a sound that one hears without seeing the causes behind it’. As ordinary as such an act of listening might seem in the present, considering the prevalence of mobile musicking devices, acousmatic sounds have been a cause for wonder in the past. Schaeffer himself dedicated the term to a form of musical composition he pioneered: musique concrète.
[ Pierre Schaeffer's practice explained ]
His compositions comprised for the greater part of sonic collages reconfigurations of recorded sound objects. Working with magnetic tape enabled him to physically rearrange the sonic material at hand, and produce sounds straight from uncanny valley. Never before had random sounds been slowed down, sped up, looped, or reversed, and it had been technology that facilitated a haunting listening experience.
In 1948 already, Pierre Schaeffer produced and presented his Cinq études de bruits: a collection of five sound collages created by the use of magnetic tape. These electroacoustic compositions consist of ambient recordings that he later edited in his Studio d’Essai in Paris. There, he edited his tapes (using scissors and adhesives) in such a way that the sounds reproduced sounded nothing like the natural sounds he had recorded. This caused for a radical development in sound recording and reproduction since sound recording was no longer an end but instead a means for music making.
[ Cinq études de bruits - Pierre Schaeffer, 1948 ]
Pierre Schaeffer's practice can be seen as sampling avant la lettre: appropriating sonic objects, editing them at will, and placing them in a broader composition. This technique has become common in current music production, if not the norm for some specific musics (e.g. hip-hop or house). The above-mentioned term acousmatic applies to such musics too as they can often impossibly be performed live without the use of pre-recorded and mechanically or digitally edited sound tracks. Hence the term live itself has been drastically altered in the second halve of the 20th century by the introduction of recorded sound manipulation and its use in music production.