Electric musical instrument

An electronic musical instrument which is capable of generating note frequencies corresponding to a plurality of kinds of temperaments and a transposition operation, comprising:

• memory means for storing note frequency data corresponding to a plurality of temperaments by steps of more than one of each transposition operation;
• a note frequency data selecting controller for selecting the note frequency data from the memory means in accordance with a selected one of the temperaments and the transposition operation;
• and
• a musical tone generator for generating, of the basis of the note frequency data selected by the note frequency data selecting controller, a musical waveform of a note frequency corresponding to the selected note frequency data;
• the musical tone generator comprising means for generating a master clock frequency and a programmable frequency divider for dividing the master clock frequency, and wherein the note frequency data is frequency dividing ratio data for the programmable frequency data, the musical tone generator also comprising an adder-accumulator for generating an output pulse when the result of an add-accumulate operation overflows and means for periodically transferring increment data for the add-accumulate operation to the adder-accumulator, and wherein the note frequency data is the increment data for the adder-accumulator;
• the memory means comprising optional memory means for storing the note frequency data individually and main memory means incorporated in the electronic musical instrument and connected via transfer means to the optional memory means, the optional memory means being detachable from the electronic musical instrument and portable.