Abstract A note an octave or two octaves below the lowest note of a chord played on the accompaniment manual of an organ is produced by a frequency-dividing flip-flop triggered by a signal selected from the chord notes by use of a preferential type of mechanical switch. This switch is comprised of a series of movable contacts parallel to, and actuated respectively by, playing keys in the lower section of the accompaniment manual. Thereby, when a chord is played, a note corresponding only with the lowest or root note of the group of keys actuated is sounded. The pitch range of such a switch is only about seven semitones, so if, as is preferable in a root tone system, about an octave and a half of semitones is to be included, some means must be provided for extending the range to about 19 semitones. The preferred extension, in accordance with the invention, is to parallel the movable contacts with ordinary make-break key switches actuating diode gates preferentially biased by scaling voltage dividers. Means are provided to have one preferential system override the other, so that a double preference is exercised, operative simultaneously over the entire 19 semitones.
In an electronic organ: a source of tone signals representing accompaniment tones of said organ; an accompaniment manual including keys and keyswitches for calling forth said tone signals simultaneously; a tone-color circuit in cascade with said keyswitches; a preference network for selecting the root tone signal of plural ones of said tone signals called forth simultaneously; a single switch; a frequency divider having an input circuit and an output circuit; means responsive to selective operation of said single switch for directing said root tone signal at will to said input circuit; a further tone-color circuit connected in cascade with said output circuit; and loudspeaker means connected to said tone color circuits for transducing the outputs of both said tone color circuits.
Claim 2
Dependent Claim
121 words
In an electronic organ: a source of tone signals representing accompaniment tones of said organ; an accompaniment manual including keys and keyswitches for calling forth said tone signals simultaneously; a tone-color circuit in cascade with said keyswitches; a preference network for selecting the root tone signal of plural ones of said tone signals called forth simultaneously; a single switch; a frequency divider having an input circuit and an output circuit; means responsive to selective operation of said single switch for directing said root tone signal at will to said input circuit; a further tone-color circuit connected in cascade with said output circuit; and loudspeaker means connected to said tone color circuits for transducing the outputs of both said tone color circuits.