Abstract: An electronic musical instrument includes an emphasis circuit for independently modifying the level of each musically encoded data channel of a selected automatic accompaniment pattern in response to a parameter characterizing key operation, such as key velocity or key aftertouch force. Channel level modification is effected by modifying the MIDI velocity data byte of each channel in accordance with a value selected from a respective emphasis table in response to the current value of the key operating parameter.

Abstract: Apparatus for producing a chorale or vocal effect in an electronic musical instrument comprises means responsive to the playing keys of the instrument for producing an indexing signal and means responsive to the indexing signal for sequentially developing a plurality of control signals. A programmable filter is responsive to each sequentially developed control signal for modifying the harmonic content of a tone signal to simulate a different vowel-like sound for producing a vocal effect consisting of a sequence of different vowel-like sounds as the keys are played. The modified tone signal may be coupled through a chorus generator to simulate a chorale effect and the programmed characteristics of the filter may be modulated to further animate the performance as well as being made responsive to a glide signal for producing two different vowel-like sounds in succession at two different pitches in response to a glissando or portamento command.

Abstract: This is an electronic organ drawbar circuit in which selection of the footage volumes is accomplished by means of a switch matrix; and sets of footage/volume correlations so chosen are stored in a memory. Another group of switches is used to select among several different memory fields, so that various sets of footage/volume data can be stored while another set of data is in use, and each stored set can be recalled for subsequent re-use.

Abstract: The disclosure describes an improved electronic musical instrument capable of simulating a sound resulting from the striking of a natural percussion instrument. The electronic instrument includes playable keys, a tone signal generator for generating tone signals and an output circuit for converting the tone signals to audible tones. A control circuit responsive to the depression of any one of the keys enables one or more of the tone signals representing one or more fundamental pitches to be transmitted to the output circuit for a first time period and enables another tone signal representing a pitch nonharmonically related to the fundamental pitches to be transmitted to the output circuit for a second time period less than the first time period. By combining the tone signals corresponding to the fundamental and nonharmonic pitches, the sound of a percussion instrument is simulated.

Abstract: A circuit for producing a chorus effect in an electronic musical instrument. The circuit includes N separate channels, where N is an integer greater than one, with each channel having an analog delay line to which a tone signal is applied. Each delay line frequency modulates the applied tone signal at a subaudio rate in response to changes in the frequency of clock pulses applied to the delay lines. The delay variations in one delay line are out of phase with the delay variation in every other delay line by a selected amount which is normally 360.degree./N. Clock pulses are generated by means including a nonlinear circuit to compensate for the nonlinearity in the frequency interval between tones in the musical scale. The outputs from the delay lines after filtering of the clock frequency components are utilized to produce the desired chorus effect output from the instrument.

Abstract: This invention relates to a circuit for use in an electronic musical instrument such as an organ, the instrument having two separate sources of bass signals and transducing elements for converting the bass signals into a sound output. The circuit is operative to prevent signals from one of the sources from being applied to the transducing elements when signals from the other source are present. For a preferred embodiment, a predetermined signal, such as a keying signal, is generated when signals from the other source are present and this predetermined signal is utilized to shunt signals from the other source to ground or to otherwise inhibit the application of these signals to the transducing elements.