The stage that a particle in vibration has reached in its CYCLE. Particles are in phase when they are at the same stage in the cycle at the same time, and out of phase when they are at opposite stages. Phase is measured by the angle of rotation, in degrees or radians.
(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.
A form of STEREOPHONIC or multi-channel reproduction in which the sound source is spread around the listener by the use of four tracks or CHANNELs in recording or transmission and the use of four (or more) LOUDSPEAKERs. Conventional music or speech may be recorded in this way, in which case the speakers behind the listener add REVERBERATION to the original sound or are simply out of PHASE with respect to the front ones; or new works may be composed in which all tracks carry original material.
If two TONEs are about 15 Hertz or less apart, INTERFERENCE will result from their similar though not exactly identical frequencies. Gradually they will move out of PHASE until at 180