JPS54143223A - Sound selecting circuit in automatic accompaniment apparatus in electronic musical instruments - Google Patents

Abstract

PURPOSE: To make intricate and highly advanced accompaniment sound play with a simple constitution by selectively outputting the frequency dividing outputs of sound source signals selected according to pitch name signals according to compass signals and forming the sound signals corresponding to the pitch names and compasses.

CONSTITUTION: The time-shared pitch name signals and compass signals having been program processed with a microprocessor are inputted to the memories M₁, M₂ of unit selecting circuits SC₁, SC₂... corresponding to respective sounds. The storage contents of the memory M₁ of the circuit SC₁ open the AND gates A₁, A₂... to which the sound source signals are applied via decoder DEC₁ and the sound source signals corresponding to the pitch names from the OR circuit OR₁ are divided by the frequency dividing circuit Div provided with multistage 1/2 dividers Div₁, Div₂... On the other hand, opening of the AND gates AND₀, AND₁... corresponding to the dividers Div₁, Div₂... is controlled according to the contents of the memory M₂ and the sound signals corresponding to the assigned pitch names and compasses are simultaneously generated from the OR circuit OR₂. The same holds true of the unit sound selecting circuits SC₂... corresponding to the respective sounds, thus the intricate and highly advanced accompaninent sounds may be readily played.

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