shown here as it was in 1966, was used to control the output of
the Sine bank, or the Multi-track (Special Purpose) Tape Recorder.
The chart paper moved past a series of light sensitive switches
and was illuminated by the light above the instrument. When the
light was blocked by a darkened area of the paper, the sound generator
would be turned on.
A row of one
hundred photocells read the information from the ten-inch-wide
graph paper which was marked with ink at points where the sound
was to be activated. As the dark sections of paper passed the
photocells, the appropriate number of oscillators generated the
sounds. By October 1959, Le Caine had synthesized several bird
sounds with the Spectrogram, which he played at a conference of
the Audio Engineering Society. Le Caine was interested in the
study of bird sounds because of their similarities to electronic
of the score for Bird Spectrogram.