In 1957, Le Caine began work on an instrument to control complex sine-wave structures. Initially he built a bank of 16 oscillators controlled by touch-sensitive keys but by 1959 he had built a much larger array of 108 (9 x 12) oscillators that were to be controlled by touch-sensitive keyboards or by the Spectrogram.

Le Caine demonstrates the Oscillator Bank for Arnold Walter and Thomas Meyer. The chart paper in his right hand will be used to control the Oscillator Bank with the use of the Spectrogram.

Le Caine (at right) demonstrates the bank of 108 oscillators at the electronic music lab at the NRC research building M-50 for (left to right) Thomas Meyer, Arnold Walter, and John Bowsher.

By 1961, two more oscillator banks, one with 12 oscillators and the other with 24, were built and operated by touch-sensitive keyboards. Each oscillator was independently tunable and produced not only sine waves but also pulse waves, square waves, and saw-tooth waves.

Since each oscillator required about one minute to tune, it took a composer almost two hours to tune a bank of 108 oscillators. The oscillator banks were used to generate electronic sounds which would be altered by standard studio methods such as playback speed on the multi-track or juxtaposition with other sounds.

Paul Pedersen of the McGill electronic music studio uses chart paper in the Spectrogram to control the sounds generated by the bank of 24 oscillators at the right.