Abstract: Pedal control circuits for use with an electronic musical instrument, such as a piano, which provide control functions analogous to the actions of a sustaining pedal, of a sustenuto pedal, and of a volume pedal of a conventional piano. Damper circuits operable in conjunction with a sustaining pedal provide an effect analogous to the action of the sustaining pedal in a conventional piano, a latching circuit actuated by depression of a sustenuto pedal operates in conjunction with the damper circuits in a manner analogous to the action of a sostenuto pedal in a conventional piano, and a volume pedal and associated circuitry is operative to determine the level of the output tones only at the moment of strike of the keys, an action analogous to that of the volume pedal in a conventional piano.

Abstract: A stop tablet mechanism particularly suited for electric organs wherein a plurality of stop tablets lie in closely spaced apart side-by-side relation, the stop tablets being pivotally supported on a tablet rail and spring-biased to assume a neutral position from which they can be momentarily moved up or down against the action of the spring.

Abstract: In a voicing system for electronic organs, square wave signals from a tone generator are converted to a waveform of another shape, the harmonic structure of which is useful for producing certain organ voices. This modified waveform is further modified, as by integration or differentiation, to produce signals of yet another wave shape whose harmonic content makes it useful for deriving still other organ voices. In one embodiment, the square wave pulses are initially converted to narrow pulses which are particularly suitable for the production of reed and certain string voices, and these sharp, narrow pulses are integrated to produce, in effect, a separate source of signals having a sawtooth waveform the harmonic structure of which is particularly suitable for production of cello, diapason and flute sounds.

Abstract: This invention relates to a electronic chorus and tremulant system for an electrical musical instrument such as an electronic piano or an electronic organ. A plurality of different sub groups of tone signals representing musical notes are separately collected from a conventional tone generating system. A bucket brigade delay line vibrato system is incorporated in each of a plurality of transmission channels each having a loudspeaker at its output. The instantaneous pitch of the signals in each channel is cyclically varied by varying the time delay introduced by its bucket brigade delay line. The instantaneous pitch in each channel is caused to be different from the instantaneous pitch of every other channel so that a multiple voice chorus effect is produced.

Abstract: In an electronic musical instrument, such as an electronic organ, the speech characteristics of reed organ pipes are simulated by applying pulses produced by key-actuated tone generators, which pulses are preferably narrow as compared to their repetition frequency, to a low-pass filter, the pass characteristic of which has a relatively sharp knee and a very rapid rate of rolloff, thereby to sharply attenuate the harmonics contained in the pulse which have frequencies above the cutoff frequency. The resultant tone passed by the filter is surprisingly reed-like in character, and by changing the cutoff frequency, reed-like voices of differing properties, imitative for example, of an organ Oboe tone, an orchestral Oboe tone, a Clarinet, a Kinura or a Trompette are obtained.

Abstract: For use in an electronic musical instrument, such as an electronic organ, a first set of tone generators, preferably of the type where all of the notes of a musical scale are obtained by frequency division from a single frequency stable master oscillator, operates together with a second set of tone generators comprised of a plurality of individually tunable chorus oscillators for generating the notes of a musical scale in a frequency range where the sensitivity of the human ear to ensemble or chorus effect is appreciable. The chorus oscillators are individually adjusted to beat with and produce chorus effects with corresponding notes derived from the first set. In addition, the entire set of chorus oscillators is capable of being simultaneously and proportionally raised or lowered in pitch by applying a control voltage to a frequency control terminal.

Abstract: An Electronic Tuning Device for tuning musical instruments employes a single radio frequency oscillator. Frequency dividers are used to divide the frequency of the radio frequency oscillator (clock) by various divisors so as to produce a series of notes that approximate a desired musical scale. A note selector selects a particular note for use as a reference frequency against which a musical instrument to be tuned can be compared. The note selector also controls means for shifting the frequency of the master oscillator slightly so as to place the frequency of the selected note exactly at its proper position in the desired musical scale. A vernier control is provided by means of which the master oscillator can be altered so as to cause all of the notes to be sharped and flated up to about a half semitone.