A tone generation system is intended for use with an electronic musical instrument of the type wherein an audible tone is generated electronically in response to actuation of the instrument by a player. The invention generates digital signals capable of defining either the waveshape or the envelope characteristic of a tone for each tone initiated by such player actuation, the amplitude thereof being varied in accordance with the intensity of the player actuation initiating that tone. To define the amplitude, digital electronic circuits (22) are utilized for developing a digital scaling signal corresponding to the intensity of actuation of the instrument by the player. Other digital circuits develop (10,18) a digital waveform segment signals which define portions of a composite waveform, as represented in an orthogonal coordinate system. Further digital circuits (24) arithmetically manipulate these scaling signals and waveform segment signals to give a composite output signal defining the envelope or waveform to be produced.