Electronic musical instrument using addition of independent partials with digital data bit truncation

An electronic musical instrument comprising a host processor (10), process/engine interface (12) and sound engine (14) the latter utilizing partial control chip modules (32, 34) and a data path chip module (36) to effect multiple partial (Fourier) synthesis, in conjunction with a sound modelling technique, to generate up to 240 independent partials and impress time-varying amplitude envelopes on them and select and apply them to sound generation, each partial being controlled by selected parameters of frequency, amplitude, phase and attack/decay rate. A modulo-sumdither and oversampling approach to noise reduction is utilized in connection with the data path chip arrangement. Log sine addition is utilized to avoid multiplication apparatus ordinarily required to combine sine wave defining parameters.