Léonce Lavallée’s ‘Sonothèque’ or “sound library” was a “coded performance electronic instrument using photo-electric translation of engraved grooves”. The instrument was capable of reading music and sounds encoded graphically with conductive ink sensed by a set of electrically charged brushes – a graphic encoding method that was used a decade later by John hanert with the Hanert Electric Orchestra .
The instrument was patented (FR806076) in 1936 as ‘Dispositif pour la reproduction sonore d’une partition de musique avec utilisation d’enregistrement de sons élémentaires’ or ‘Device for the sound reproduction of a musical score using the recording of elementary sounds’ and, according to Le Caine was demonstrated in Paris in 1929:
“The first public demonstration of “synthetic music” made by electronic devices was at the Paris Exposition of 1929, where a roll-operated device consisting of four monophonic electronic oscillators was shown with great success. Following the basic patent covering this device,*” there are other similar French patents. In one of these,“ a number of different devices are described, that allow the composer or arranger to draw by hand the sound envelope. In one form of the invention, the arranger engraves a groove in a suitable support which varies either in depth or in position at right angles to the time axis. When the music is reproduced, a needle following the groove operates an optical wedge to control the light passing through a sound-on-film recording to a photocell. In another form of the invention, the arranger draws by hand in conductive ink, a mark of varying width or position which is read by a series of brushes to set up the sound envelope. As a sound source, the inventor uses a “sound library” (sonothéque) consisting of suitable supports on which are recorded by any known method the various notes of the various instruments, in addition to vocal sounds and other noises. As an alternative, synthesis from pure tones is mentioned.”
Thomas LaMar Rhea. ‘The Evolution of Electronic Musical Instruments in the United States’ 1972
Hugh Le Caine, ‘Electronic Music’, Proceedings of the IRE, 44 (1956), pp. 457–