An envelope generator for use in an electronic instrument generates an envelope waveshape control voltage having separate attack, first decay and second decay sections. The control voltage representing each waveshape section is derived from a separate voltage divider network. The divider networks are connected in series, with separate voltages supplied to the ends and junctions thereof. These supplied voltages correspond to the initial, attack, sustain and final voltage levels of the generated control voltage. The output nodes of the separate divider networks are accessed at different clock rates.A scanning circuit sequentially enables consecutive pairs of gates associated with each divided voltage output node. These gates alternately are connected to separate first and second output lines which provide divided voltages from adjacent gate pairs to opposite ends of an interpolation circuit. This circuit interpolates the provided voltages to derive the envelope waveshape control voltage. As consecutive pairs of gates are enabled, the interpolation circuit reverses the order in which the interpolation is performed.