(French: concrete music) A development introduced in Paris in 1948 by Pierre Schaeffer at the studio of the French Radio (O.R.T.F.). Its aim was to replace traditional musical material with recorded (i.e. concrete) sounds which were then manipulated by FILTERing, tape reversal, TAPE LOOPs, speed changes, tape SPLICEs, or other electronic means. The source of all sounds, however, was environmental. The experimental side of this study developed the concept of l'objet sonore.