Electronic musical instrument capable of fill-note generation

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. If the depressed lower key is of a note name above that of the depressed upper key, on the other hand, then the note-coded data of the depressed lower key are combined with octave-coded data indicative of an octave just below that of the depressed upper key. The key-coded fill-note data thus formed are fed into a multichannel tone generator circuit, along with the key data representative of the depressed upper and lower keys.