Abstract: A fully digitalized function-of-time generator suitable for use as a tone envelope generator in a digital electronic musical instrument, comprising: a clock pulse generator for generating a clock pulse at a selectable rate; a gate enabled at each arrival of the clock pulse; a single-stage binary shift register for successively shifting out its contents as a digital word representing the instantaneous values of a desired function of time synchronously with the clock pulse; a digital subtractor; a digital multiplier; and a digital adder, all of these members being interconnected to each other to be operative so that the output of the register is subtracted from a first set value representing a digital word, the resulting difference being multiplied by a second set value representing a digital word, the resulting product being added to the output of the register via the gate, so that the resulting sum is loaded into the register.