Abstract: An electronic musical instrument includes circuitry for modifying an ordinary address signal which changes at a uniform rate over one cycle of a waveform, into a modified address signal whose rate varies in one cycle of the waveform by the use of a modification signal.The modified address signal accesses a storage device such as a ROM in which waveform data is stored, thereby producing the modified waveform data from the storage device. The modification signal is obtained from the ordinary address signal through a predetermined logic circuit.

Abstract: Code data representing a plurality of note frequencies are stored in a first ROM and are selectively read out according to key operation of a keyboard. With the operation of a key, predetermined control data is also obtained, and this control data is cumulatively added to or subtracted from the code data as an initial value, whereby a note frequency signal corresponding to the operated key is obtained. Portions of the waveform of the resultant note frequency signal where there is a sharp change in amplitude are interpolated with a sine wave stored in a second ROM.

Abstract: An electronic musical instrument includes circuitry for modifying an ordinary address signal which changes at a uniform rate over one cycle of a waveform, into a modified address signal whose rate varies in one cycle of the waveform by the use of a modification signal.The modified address signal accesses a storage device such as a ROM in which waveform data is stored, thereby producing the modified waveform data from the storage device. The modification signal is obtained from the ordinary address signal through a predetermined logic circuit.