120 Years of Electronic Music

The "Welte Licht-Ton Orgel" (Light-Tone organ) (1936)

A detail of one of the the Light Tone Organ's glass disks. Click to enlarge

The Welte Light-Tone, designed by E. Welte in Germany, 1936. The Light Tone organ was one of a number of electronic instruments of the time that generated and controlled sound using a opto-phonetic technique (see: "The Superpiano", Pierre Toulon's "Cellulophone", Ivan Eremeef's "Syntronic Organ" and "Photona", the Radio Organ of a Trillion Tones, the Polytone Organ, Daphne Oram's "oramics" and others).

The instruments sound generation unit consisted of 12 glass disks which were printed with 18 different looped waveforms in concentric rings. The glass 'tone wheel' disks were rotated over a series of photoelectric cells, filtering a light beam that contolled the sound timbre and pitch. The resulting combinations of tones gave 3 different timbres for all the octave registers of each note on the keyboard.

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