Abstract: A three-keyboard electronic musical instrument of the type generating binary-coded primary key data representative of notes played on the keyboards, and secondary key data representative of unplayed notes that are correlated with the played notes in some musically favorable way. Prior to introduction into a multi-channel tone generator circuit, part of the primary key data and all of the secondary key data are directed into a key data memory having storage channels corresponding in number to the sounding channels in the tone generator circuit available for such data. A discrimination data memory has a plurality of storage locations, corresponding to the storage channels of the key data memory, for storing binary-coded data representing the discrimination between the primary and the secondary key data stored on the corresponding storage channels of the key data memory.

Abstract: A polyphonic, keyboard-type electronic musical instrument capable of automatic production, in response to key depressions on upper and lower keyboards, of "fill notes" which bear the same note names as the depressed lower keys but which, preferably, fall within an octave below the lowest pressed upper key at every moment. The instrument is of the type wherein each depressed key is coded into key data in accordance with a binary "key code" composed of a note code and an octave code. The note code identifies the note name of each key, whereas the octave code identifies the octave to which the key belongs. Upon depression of a key on each of the upper and lower keyboards, the note-coded data derived from the key date representative of the depressed lower key are combined with the octave-coded data derived from the key data representative of the depressed upper key if the note name of the depressed lower key is below that of the depressed upper key.

Abstract: An electronic musical instrument comprises a key on-off memory for storing the on-off state of the respective keys, and at a time counter for counting the lapse of time after release of the respective keys. The time counter inhibits generation of the musical tone signal corresponding to the key when the conditions that predetermined time is elapsed after the key release and that the key-off state is stored in the memory are satisfied. This inhibition is separately conducted with respect to the keys. Thus, it can remarkably prevent noise when the tone should not be produced.