Harold G. Alles

Real time digital sound synthesizer

Linearly binary-coded digital control signals representing specific time segments of musical sounds are used in part to control stepped ramp signal generators in a digital synthesizer which runs continuously on a fixed program. The ramp signals are used to control amplitude and frequency parameters of multiple digital oscillators that produce respective constituent tones of the musical sound segments. The synthesizer is operable in response to time-multiplexed digital control signals for multiple musical voices, one voice portion of which is also being computed in real time for multiplexing with previously computed and stored digital control signals for other voices. The indicated computations are effected by known techniques on a commercially available computer to translate performer-actuated transducer output signals, designating notes of a composition, into the aforementioned binary-coded digital control signals.