The use of noise, defined as an indeterminate complex of sound, initiated a radical shift of the field of “music.” Between Pierre Schaeffer and John Cage there is a common point : against the hierarchical principals that rule music, they both pose equality of all sound material. Examining the case of Pierre Schaeffer and musique concrète, this essay asks how noise, as a raw material, breaks the logic of mimesis. How does this material imply new ways of composing or listening, a new “partage du sensible”?