Sémaphora III

From 1965, Couchot realised a series of "cybernetic" objects, which he called "mobiles musicaux" [musical mobiles]. These artefacts consisted of movable, coloured light elements arranged on a vertical surface measuring 1x2 metres. They reacted to acoustic stimuli through light and movement, whereby the machine determinism of the reactions was varied by random operations. As there were no microcomputers at the time, Couchot developed simple electronic circuits himself. 

Initially, Couchot built »Semaphora I,« an object that reacted to radio waves. By turning a knob that changed the radio programme, the illuminated and moving structures changed. 

In 1965, Couchot presented a second mobile, "Semaphora II", which could react to music, in Paris under the auspices of the ORTF music research group (then headed by Pierre Schaeffer). This was followed in 1966 by a third mobile, »Semaphora III,« which was based on the same principle but was more complex and was presented at the V Biennale in Paris in 1967.

Couchot's intention was to give these artefacts a certain autonomy when they responded to works of contemporary music such as those by Pierre Schaeffer, Bernard Parmegiani, Pierre Boulez and Luciano Berio. 

In the catalogue of the V International Biennale in Paris in October 1967, Couchot noted about »Semaphora III»:

"Even if this mobile can obey the sound, it is not passively docile, for it opposes this kind of aggression, which comes from outside, with a resistance strong enough to consider the play of evoked images as the product of a sensibility open to the world of sound and an inner reaction proper to the mobile".