Abstract: The present invention relates to a keyer capture system for an electronic keyboard musical instrument, such as an electronic organ. The system is particularly adapted for the situation wherein a relatively low number of notes are required to be captured at one time, such as in the case of the pedals. The system is responsive to serial data for the pedals and the two keyers are captured on a priority basis with the master keyer given preference. If the note is already captured by the other keyer, then that note will not be captured by the keyer which is receiving the keydown pulse for that note, and a recirculating shift register for each keyer keeps track of which note that keyer has captured. The system is capable of being easily integrated into an electronic organ wherein the pedal data is in serial time division multiplexed format, and can be implemented as an accessory wherein it is desired to generate the pedal data from the lowest actuated key on one of the manuals.

Abstract: A method and apparatus for memorizing and playing back an accompaniment passage in an electronic organ wherein the keyboard is multiplexed to develop a serial input data stream having keydown signals in the time slots corresponding to the depressed keys, selectively writing into a programmable random access memory data corresponding to the absolute address of the first occurring keydown signal in the pulse train and then writing into the memory data corresponding to the intervals, expressed in terms of time slots in the multiplexed data stream, between a number of the first occurring keydown signals, beginning with the first occurring signal. The data is read out of the memory and converted to a serial time division multiplexed data stream by means of comparators which produce a pulse each time there is a compare condition between the output of the memory and the count produced by the master counter/subcounter.

Abstract: Circuitry in an electronic organ for electronically storing a series of signals corresponding to depressed keys depression and for recalling the stored series in response to player commands.The circuit allows the player to play accompaniment chords of a piece of music alone and at any desired pace, and then while manually rendering the righthand, or solo, portion of the music. The chords are played by simply depressing a single control button whenever the next chord in the stored series is required.A further feature of the invention is the ability to store sets of switch or tab or other selector element settings for later recall. The selector element setting storage circuit enables the player to switch tab settings during storage of chords, while storing the patterns in the order in which they will be desired.

Abstract: A variable filter circuit, especially for synthesizing and shaping tone signals, in which a variable light source is provided which influences light sensitive resistor elements in the filter circuit. The variable circuit, by the use of selector switches, can provide different musical features, such as muted voices, percussion, brass, woodwind and the like, all of which will enhance, for example, existing organ voicing while it is, furthermore, possible to obtain the effect of playing a solo instrument together with organ voicing.

Abstract: A method and circuitry for frequency generation, especially for electronic organs, in which a digital signal is developed by the actuation of an element such as a key of an organ keyboard. The digital signal is converted to a respective voltage signal and the voltage signal is employed to control a voltage controlled oscillator which supplies a signal corresponding in frequency to the actuation of the aforesaid element. An organ provided with a system for frequency generation according to the present invention can be operated monophonically or polyphonically and is capable of producing desirable effects, including celeste and portamento effects.