Abstract: An electric guitar having a vibrato function includes first and second operation elements and an operating unit. The first operation element can designate a pitch width to be changed by setting a first pitch width as a unit. The second operation element can designate a pitch width to be changed by setting a pitch width smaller than the first pitch width as a unit. The operating unit performs an operation of the pitch width to be changed, which has been designated by the first operation element, and of the pitch width to be changed, which has been designated by the second operation element. The operating unit forms the control information representing a width of pitch change of a vibrato to be imparted on the basis of the operation result, thereby imparting the vibrato effect on a musical tone to be produced in accordance with the control information.

Abstract: A control circuit for shaded-pole motors used in an acoustic pulsato system for producing special musical effects. The system includes a horn-type loudspeaker connected to a shaded-pole motor and/or a drum-type loudspeaker connected to a shaded-pole motor. Each type of loudspeaker has a feedback circuit and a means for the operator to select the desired speed for the motor. The feedback circuit quickly adjusts the actual speed of the motor to correspond to the selected speed by controlling the amount of current or power supplied to the motor. The drum-type loudspeaker feedback circuit also includes a braking circuit to quickly stop the motor and the drum rotation to prevent unpleasant spurious signals which occur if the drum loudspeaker is permitted to coast to a stop on a slower speed.

Abstract: A digital pitch bend signal is supplied from an A/D converter to a first coefficient multiplier for every predetermined sampling period. An output of the first coefficient multiplier is added with an output of a second coefficient multiplier at an adder an output of which is delivered, as a digital pitch bend signal in the present cycle, from a buffer for the tone generation. The output of the adder is also fed back to an input of the second coefficient multiplier. Thus, from the buffer, a converted pitch bend signal having a value corrected during the respective sampling periods is produced.

Abstract: An electronic musical instrument comprises a plurality of keyboards each having a plurality of keys, a control circuit for controlling a manner of tone production, and a musical tone production circuit responsive to respective depressed keys of respective keyboards. The control circuit controls the musical tone production circuit in response to operation of a switch mounted on a control panel for manually selecting one of a plurality of sets of preset parameters corresponding to a kind of a musical tone to be performed. The musical tone production circuit modifies a tone specified by a depressed key in any keyboard according to the selected switch on the control panel.

Abstract: Tone signals from plural keyboard systems are supplied to an effect imparting circuit via a distribution circuit. The effect imparting circuit comprises plural effect imparting channels and the device can impart a tone effect independently to a tone signal provided to each of the effect imparting channels. The distribution circuit distributes tone signals from the respective keyboard systems to any one or more of the effect imparting channels. An effect selection device is provided for selecting tone effects for the respective keyboard systems and an effect assignment device is also provided for assigning the effects selected in the respective keyboard systems to any of the effect imparting channels according to the selection by this effect selection device. The distribution circuit delivers the respective tone signals to the proper effect imparting channels respectively as controlled by the effect selection and the effect assignment.

Abstract: An electronic musical instrument which employs frequency numbers and is capable of producing a natural and expressive effect such as vibrato or the like with a simple structure. The electronic musical instrument is provided with a frequency number memory for storing a frequency number corresponding to the note of each key and a frequency number for modulation prepared for each key corresponding to frequency modulated data, a frequency modulated data generating units for selectively generating glide data and vibrato data, and an key assignor for generating key depression information and keyboard information. The key depression information being used to address a high-order address of the frequency number memory and the low-order address of the frequency number memory by being addressed frequency modulated data available from the frequency modulated data generating units.

Abstract: A device for controlling tremolo effects and electronic sound effects in an electric stringed instrument, which comprises;manipulable means communicating with, and capable of providing control of, means for producing tremolo effects.A portion of the manipulable means being itself individually manipulable and communicating with and capable of providing control of, means for producing electronic sound effects. The manipulable means and portion thereof being capable of individual, simultaneous manipulation to control tremolo and electronic sound effects.

Abstract: A sound effect imparting device for an electronic musical instrument is capable of imparting a plurality of desired sound effect such as vibrato and reverberation effects to a digital musical tone generated from the electronic musical instrument. The device comprises a digital arithmetic operation unit constructed with a combination of adders, multipliers, delay circuits, etc., a control unit, a parameter memory and a read-out unit.By control data and parameter data which are respectively read out from the control unit and the parameter memory by means of the read-out unit, switching of the operation mode of the digital arithmetic operation unit is controlled in a time-sharing manner, whereby a plurality of sound effects are imparted to a musical tone through digital arithmetic operations.

Abstract: A keyboard operated electronic musical instrument is disclosed which has a number of tone generators that are assigned to actuated keyswitches. Logic is provided for generating a note range signal for each preselected group of contiguous keyswitches in which the note range signal is selected for an actuated keyswitch. Musical effects such as vibrato and tone changes are selectively actuated in response to the note range signal. A mixture tone generator is described which uses a single set of harmonic coefficients which are translated and shifted in response to the note range signal.

Abstract: In an electronic musical instrument which is equipped with the function of producing both glide and vibrato effects, a circuit is provided so that when the glide effect starts to restore to its ordinary pitch, delayed vibrato is started, thereby eliminating an effect during the switchover from the glide effect to the vibrato effect.

Abstract: An electronic musical instrument wherein purely digital techniques are utilized for generating the basic waveform train and also keying the waveform train so as to have the customary keying envelope with attack, sustain and decay portions. The wavetrain is a cyclically repeated series of four-term Blackman-Harris window functions, wherein there are preferably eight such functions in each series. A plurality of individual keying envelopes are generated by a piecewise linear technique, and these envelopes are assigned respectively to the waveforms in the series so that the relative amplitudes of the waveforms can change with time over the life of the tone. This results in modulating with time the harmonic content of the tone.

Abstract: Electronic circuits are provided for producing an electronic timbre modulation for effecting celeste or vibrato similar in sonic results to the well-known Leslie rotating speaker system. Electronic signals corresponding to audio tones are generated and are modified by appropriate filters. Three controlling oscillators are locked in exactly 120.degree. phase relation to one another and act through three voltage controlled oscillators respectively to modulate three bucket brigade circuits through which said modified electronic signals are passed substantially in parallel. A roving band pass filter further modulates those of said electronic signals corresponding to flute tones to simulate other aspects of a Leslie speaker system.

Abstract: An electronic musical instrument comprises a plurality of musical tone control units each having a tone waveform producing circuit, a volume envelope circuit, a filter circuit and other circuits. A given musical tone data can be preset in each musical tone control unit. Musical tone signals produced by the musical tone control units are synthesized to provide an effective musical tone.

Abstract: A plurality of sets of such characteristics as the color, volume and effect of a musical tone are preset for different musical composition fashions. Desired preset characteristics are selected independently in the melody performance portion and the accompaniment performance portion by operating a corresponding melody musical composition fashion selection switch and a corresponding accompaniment musical fashion selection switch thus establishing a musical tone having a desired musical composition fashion for each portion. According to a modified embodiment, when either one of the melody and accompaniment musical composition fashion selection switches is operated, both the musical composition fashions of the melody performance portion and the accompaniment portion are established in predetermined manner.

Abstract: An electronic reverberation system for use in an electronic musical instrument comprises a random access memory wherein two or more time delay channels are defined by address allocation in a controller circuit. An input analog signal is converted to digital signals by an analog-to-digital converter and the digital signals are processed by the controller into the time delay channels. The channels defined in the random access memory are of differing lengths which can be changed by switch settings. The controller sequentially retrieves stored digital data words from the random access memory channels in seriatum and couples each data word to a digital-to-analog converter. The analog output signal from the digital-to-analog converter is delayed in time by varying amounts due to the length of the channels in the random access memory. A portion of the delayed analog output signal contained in each channel is mixed with the input analog signal to produce a combined signal.

Abstract: A string chorus generator in an electronic musical instrument that accepts a single audio input signal, applies it to three separate delay lines, and provides delay modulated outputs to be used in producing an ensemble musical effect resembling a group of strings in a string orchestra. Each of the three delay line channels is identical and comprises an analog shift register driven by a high frequency voltage-controlled oscillator along with appropriate filters and buffers. The frequency of the voltage-controlled oscillator of each channel is controlled by the filtered output of a microprocessor, thereby providing precise control over the modulation of each voltage-controlled oscillator. The modulating waveshape is generated by using a lookup table within a microprocessor and comprises a sine wave of 6.25 Hz superimposed on another, larger amplitude, sine wave of 0.78 Hz.

Abstract: In an electronic musical instrument having at least one keyboard with keys corresponding to the notes of a musical scale apparatus for controlling the dynamic frequency modulation of tones reproduced from key pulses associated with active keys of the keyboard including a tonal effect control for selecting one of the desired modulation effects, vibrato, delayed vibrato or decayed vibrato, a multiplexed counter having a plurality of distinct sequential time periods for creating a delay proportional to its counting rate for generating output signals for controlling the time variant parameters of the modulation effects, a triggering means for initiating individually a count in each of the time periods of the counter in response to the generation of a key pulse, at least one count source for controlling the counting rate of the counter, a comparator for disabling the count in any of the time periods of the counter and timing alignment means for realigning the output signals of the counter with the corresponding ke

Abstract: A tone generator system for electronic musical instruments includes a voltage-regulated, high-frequency oscillator. The output of the oscillator is connected with the inputs of first and second 12-tone divider circuits having outputs for transmission of full octaves of tone signals. The connection between the output of the oscillator and the input of one of the divider circuits contains circuitry which intercepts each n.sup.th signal of the series of signals transmitted by the oscillator so that the one divider circuit is out of tune with the other divider circuit. The number n can be varied by a battery of switches and can be as low as 2 or higher than 128. An auxiliary signal dividing circuit can be connected between the output of the oscillator and the input of the other divider circuit.

Abstract: An electronic musical instrument comprises a sound generator connected to a loudspeaker by way of several parallel channels including respective delay lines constituted by charge-transfer devices of the bucket-brigade type stepped by different high-frequency pulse generators. Each pulse generator comprises a voltage-controlled oscillator whose output frequency is varied by a composite periodic signal obtained from a respective stage of a chain of operational amplifiers each provided, except possibly for the first stage, with an RC network acting as a frequency-dependent phase shifter for a nonsinusoidal modulating signal consisting of at least two sub-audio-frequency components. The modulating signal may be synthesized from a plurality of stepped waveforms generated by the concurrent readout, at different sampling rates, of a set of amplitude values stored in a read-only memory.

Abstract: In an electronic musical instrument of a digital processing type, an operation of a key causes the generation of a digital value corresponding to the operated key and a tone having a frequency determined by that digital value is produced. The instrument comprises a key assigner which assigns the operated keys from among a large number of keys to a small number of channels, which small number is a number of maximum available tones to be produced simultaneously. The instrument further comprises a modifying value generator for generating modifying values for the respective channels, the value being a first value upon key operation and subsequently varying to a second value to provide an attack pitch fluctuation effect. The key assigner and the modifying value generator are of a time division multiplexing type with the channels being defined by the corresponding time slots.

Abstract: A hybrid organ is disclosed wherein many of the musical tones comprising the complete musical instrument are produced by wind blown pipes. Other tones are produced by an electronic tone generating system and produced by loudspeakers. The electronic tone generating system is adapted especially for this purpose and includes simplified means for keeping the electronically produced tones in tune with the organ pipes in spite of the fact that the pipes change their pitch with even slight temperature and other atmopsheric changes.

Abstract: An electronic musical instrument of the type producing pipe organ-like sounds including a circuit for simulating wind noise by causing a random perturbation from the nominal frequency of tune, which an organ flue pipe exhibits when sounding, through the use of digital noise generators which are utilized to approximate an analog white or random noise source. The digital noise generators produce digital noise signals which are used to frequency modulate the instrument tone generator to produce substantially random perturbations in tbe generator output signal frequency. The present invention may be used with musical instruments having a single tone generator system composed of either a multiplicity of oscillators with a vibrato input, or a top octave frequency generator integrated circuit and a single oscillator with a vibrato input, or a transposer system.

Abstract: A two-phase, period-proportional voltage-controlled oscillator circuit is provided for clocking an analog delay line which can be used, for example, in an electronic musical instrument. The voltage-controlled oscillator circuit provides two clock output signals of opposite phase and having a period directly proportional to the control voltage, i.e., the frequency of the two clock signals is inversely proportional to the control voltage. Since the delay provided by the analog delay line is directly proportional to the period of the clock signals, the delay is directly proportional to the control voltage thereby eliminating a source of distortion in a delay modulation system.

Abstract: A keyboard operated electronic musical instrument in which a number of tone generators are assigned to actuated keyswitches. When a keyswitch is actuated, a tone generator is assigned with a musical waveshape selected from a library of waveshapes which are ordered in a predetermined arrangement. The assignment of waveshapes is made in a priority order according to the musical frequencies associated with the actuated keyswitches so that a chorus effect is obtained in which each note of a group of simultaneous notes has its own tone color. The assignment of waveshapes is made in an adaptive manner so that the melody line retains its own distinctive sound even when the number of notes played simultaneously on a keyboard changes. Vibrato effects can selectively be applied to any of the set of waveshapes.

Abstract: A detuning control circuit is provided for producing a pitch variation effect in an electronic musical instrument. The instrument includes at least one integrated circuit tone generator chip having at least one tone generator and a detuning circuit responsive to a predetermined detuning control signal for detuning the signals produced by the tone generator. The detuning control circuit comprises a detuning control signalling circuit for producing a predetermined detuning control signal and for selectively applying the predetermined detuning control signal to the detuning circuit of the tone generator chip so as to produce a predetermined pitch variation effect.

Abstract: A continuously varying electrical signal representing an original musical sound is divided at a selected mid-frequency of about 800 Hertz to provide upper and lower frequency signal bands which are then frequency-modulated with separate modulation signals that differ in frequency or amplitude or both, in order to produce a vibrato or tremulant effect and thereby enrich the harmonic content of the musical sound.In order to inject the vibrato or tremulant into each signal band, the modulation process utilizes a pulse sampling and delay circuit which minimizes clock pulse noise by selecting only the central part of each delayed pulse, and which also senses the original amplitude envelope of the unmodulated wave in order to augment the envelope that is recreated from the delayed pulses after they are recovered.

Abstract: In an electronic organ including at least two frequency controlled delay circuits controlled by varying frequency output signals from individual voltage controlled oscillators, an analog modulating and intermixing circuit provides an even vibrato effect by controlling the input signal to the voltage controlled oscillators. The amplitude of a vibrato signal which is mixed with a main voltage control signal for a voltage controlled oscillator to provide a vibrato effect is modulated by the primary voltage control signal. The primary voltage control signal is amplified and passed to the control input of a voltage controlled amplifier which receives the vibrato signal. The amplified primary voltage control signal is mixed with the output of the voltage controlled amplifier to generate the control signals for driving the voltage controlled oscillators.

Abstract: A time-modulated delay system having an input and a plurality of time-modulated output taps including storage means having a multiplicity of storage locations for storing successive portions of an interval of the input signal; a write address generator circuit for designating the address of locations in the storage means in which the successive portions of the input signal are stored; an output tap identifier circuit for sequentially identifying each output tap; a read address generator circuit responsive to the tap identifier circuit for designating a random address in the storage means from which a portion of the input signal is to be read for each time-modulated tap identified to produce a random modulation of the temporal pattern of the output taps; and a distribution circuit, responsive to the output tap identifier circuit, for delivering each portion of the input signal read out of the storage means to the corresponding identified tap.

Abstract: A timbre-select type electronic musical instrument in which the application of a sound effect unsuitable for the selected timbre is automatically blocked. This instrument includes means for detecting that a certain timbre is selected and means responsive to the signal from said detecting means for preventing the unsuitable effect for the timbre from being applied to a sound.

Abstract: An electric mouth organ holder containing a microphone therewithin and comprising an outer shell upon which are supported radially outwardly projecting harmonicas and a central core section rotatable with respect to said outer shell. The harmonicas are rotatably juxtaposed adjacent to said central core section as desired with individual harmonicas of different keys or types being thereby operatively associated with said microphone.

Abstract: An electronic musical instrument which is provided with a note frequency data memory for storing note frequency data corresponding to data of key switch depression through a key code register, a note frequency data register for latching and storing the data from the note frequency data memory by a time division pulse from a time division control signal generator, an octave data register for latching and storing octave data from the key code register by the time division pulse from the time division control signal generator, a frequency generator composed of a programmable counter supplied with the output from the note frequency data register to provide a frequency corresponding thereto, a frequency divider array supplied with the frequency and a decoder supplied with the output from the octave data register, the outputs from the respective output ends of the frequency divider array being selected by the output from the decoder in accordance with the octave data, and a musical waveform generator composed of fi

Abstract: In a device for annexing a reverberation sound similar to natural reverberation in the course of sound recording, an elastic raw material such as a leaf spring is bent into a bridge element of any shape such as a stanchion ( ), or M-shape provided with a pair of rising foot portions. The bridge element is interposed in an intermediate portion of a coiled spring which is spanned between a drive-transducer and a pickup-transducer. Vibration which is applied along the helical direction of the coiled spring is transmitted, and at the same time the compressive movement of the coiled spring induced by said vibration is absorbed by means of spring action of the bridge element, thereby flutter modulation caused by the compressive movement of the coiled spring can be prevented. Moreover, irregular bending of any portion of the bridge element in front or rear direction can prevent induction of resonance in the audio frequency range.

Abstract: An electromagnetic pickup for stringed instruments such as a guitar includes a pickup coil that is mechanically oscillated at variable frequencies in the field of the magnetically polarized instrument strings for producing an effective tremolo output signal.

Abstract: An improved mounting for an acoustic pulsato rotor for suppression of spurious sounds utilizes a spring bias for axial thrust between the shaft ends and bearing cups. In one form, a plurality of thin spider legs extend from a rotor mounting panel in surrounding relationship to the rotor to provide the spring characteristics while being acoustically transparent to the sound radiation pattern that sweeps past. The spider legs have a quick fit, anti-noise twist lock connection to a central hub. Improved rubber-like grommets provide anti-shock and anti-noise mounting for the shaft. Improved rubber-like grommets in cooperation with a two part motor mounting provide anti-shock and anti-noise motor mounting without sacrifice of simple belt tension adjustment capability. A light weight back enclosure for the speaker acquires sound isolation characteristics of a sturdy structure by imposing stress on the enclosure.

Abstract: An electronic musical instrument for producing a vocal sound signal comprising a musical tone signal generator connected to a passing circuit for passing a musical tone signal under the selection of a key. A formant filter is connected in the passing circuit and includes a plurality of filters connected in parallel to one another. A control system is operative to produce two output signals in the passing circuit after the formant filter in sequence upon operation of the key, one of the output signals being a vowel sound and the other a consonant sound.

Abstract: A brass keyer system for an electronic organ wherein the keyboard is multiplexed to produce a polyphonic serial data stream, which is then converted to a monophonic serial data stream containing a keydown signal in a time slot corresponding to the highest note played on the keyboard. The monophonic data stream is converted to a multiple bit binary word that is used by the tone generation and keying portion of the system to produce a rectangular wave tone corresponding in frequency to the highest depressed key and having amplitude and pulse width modulation on attack and decay so as to produce a brass tone. The monophonic serial data stream is demultiplexed by means of a recirculating delay loop which repetitively recirculates the keydown pulse for the depressed key. The number of recirculations of this pulse are counted by a first counter and the position of the pulse within the delay loop is registered by a second counter, which is synchronized with the multiplexer.

Abstract: A device for producing a chorus effect for an electronic musical instrument. The device has two sets of parallel time delay modulating circuits with each set having two circuits therein and the circuits being adapted to have the musical tones from the electronic musical instrument supplied thereto. Saw-tooth wave generators are coupled to the respective time delay modulating circuits for supplying the respective time delay circuits in each set with a saw-tooth modulating wave having a gradually increasing slope and a sharply decreasing slope, the saw-tooth wave supplied to one circuit in the set having the gradual slope increasing in the positive direction and the saw-tooth wave supplied to the other circuit in the set having the gradual slope increasing in the negative direction so that the waves in the set have opposite polarities, and the saw-tooth waves for one set of modulating circuits being 180.degree. out of phase with the saw-tooth waves for the other set of time delay modulating circuits.

Abstract: A keying arrangement for electronic organs in which a tone signal consisting of a square wave having, for example, a fifty percent duty cycle is connected to the input of the keyer circuit, and the output thereof, upon the depression of a playing key, consists of a pulse train with the amplitude rising at a controlled rate and the pulse width or duty cycle decreasing at a controlled rate but lagging the increase in amplitude so as to closely duplicate the playing of a muted brass instrument in the attack fashion. A muted brass tremulant affect is achieved by applying a cyclically time variant signal to modulate the pulse amplitude and pulse duty cycle, again with the change in duty cycle lagging the change in amplitude. The circuitry for accomplishing this comprises a diode keyer wherein a pair of resistor-capacitor circuits having different time constants control the keyer to effect variations in pulse amplitude and duty cycle over respective intervals of time.

Abstract: Linearly binary-coded digital control signals representing specific time segments of musical sounds are used in part to control stepped ramp signal generators in a digital synthesizer which runs continuously on a fixed program. The ramp signals are used to control amplitude and frequency parameters of multiple digital oscillators that produce respective constituent tones of the musical sound segments. The synthesizer is operable in response to time-multiplexed digital control signals for multiple musical voices, one voice portion of which is also being computed in real time for multiplexing with previously computed and stored digital control signals for other voices. The indicated computations are effected by known techniques on a commercially available computer to translate performer-actuated transducer output signals, designating notes of a composition, into the aforementioned binary-coded digital control signals.

Abstract: A tone generator for use with an electronic musical instrument includes a binary counter operated by a binary comparator and a source of clock signals for incrementally advancing or decreasing the state of the counter from a first selected state to a second selected state. The states of the counter control a programmable divider which develops corresponding output tone signals. The counter produces multiple state changes between the selected states so that each individual state change results in a frequency change which is inaudible. The overall effect is to thereby synthesize a tone signal creating the illusion of a continuous pitch change between the pitches corresponding to the selected counter states. The source of clock signals includes a rate multiplier programmed according to the states of the counter to compensate system operation for insuring that similar musical effects defined by corresponding musical intervals are produced in equal time intervals.

Abstract: A voltage-controlled type oscillator utilizing charging and discharging of a capacitor. The oscillation frequency is made to vary in exact proportion to the control voltage by variably controlling electric charge in accordance with the control voltage during charging and discharging of the capacitor.

Abstract: An electronic musical instrument system comprising an electronic musical instrument body and a separate tone cabinet connected together by a cable. The electronic musical instrument body includes a plurality of tone coloring circuits to produce different musical tone signals, a musical tone signal selection circuit to select at least one of the output signals of these tone coloring circuits, and a musical effect selector; and the tone cabinet includes a musical effect imparting circuit to impart the selected musical tone signal or signals with a selected musical effect, a sound system having at least one loudspeaker connected to the musical effect imparting circuit, and a control circuit responsive to the musical effect selector for producing control signals to cause the musical effect imparting circuit to impart a selected musical effect to the selected musical tone signal or signals.

Abstract: In an electronic musical instrument of a numerical value processing type, an operation of a key causes the generation of a numerical value corresponding to the operated key and a tone having a frequency determined by the numerical value is produced. A vibrato effect is obtained by periodic modification of the value. The instrument comprises a circuit which generates a periodic signal having a portion in which the amplitude of the periodic signal increases at a predetermined rate, and a succeeding portion having a constant amplitude, and a circuit for varying the rate. The rate varying circuit sets the rate to be either a low rate that can be discriminated by human ears or a high rate that can not be discriminated by human ears.

Abstract: This invention relates to tone generating systems for polyphonic electronic musical instruments. The system includes a plurality of programmable tone generators each of which is assigned to a different note to be sounded. For a preferred embodiment, one of the programmable tone generators is designated as a solo high tone generator, and is always utilized to produce the highest note to be sounded. Another generator may be designated as the solo low generator, and will always be utilized to generate the lowest note to be sounded. Additional solo note generators may be provided if desired. Tone generators are interconnected in a priority scheme with one generator at a time being designated as the next generator to be assigned a note to be sounded, and the designation being advanced in a predetermined manner as notes are assigned successively to the generators.

Abstract: Apparatus for chorus effect in an electronic musical instrument in which a passing circuit for a musical tone signal is obtained from a musical tone signal generator by operation of a key. The passing circuit is connected to a plurality of variable delay circuits which are individually controlled by a plurality of delay control signals generated by a delay control signal generator. The passing circuit for the musical tone signal has a format filter, as well as a keying signal generating circuit. An output terminal of this keying signal generating circuit is connected to a voice production initial stage change control signal generator. The latter control signal generator has an output terminal connected to the musical tone signal generator or the delay control signal generator.

Abstract: A waveform generator used for electronic musical instruments comprising a resistance device having a plurality of power source electrodes and a plurality of potential detecting electrodes. Electric current is supplied to the power source electrodes and potentials are periodically detected through scanning from the potential detecting electrodes by the use of a scanning circuit mechanism.

Abstract: A device for producing a chorus effect in an electronic musical instrument. An electronic delay circuit and a non-modulating amplifier means are coupled in parallel and the outputs are mixed in a mixing amplifier. A carrier oscillator is coupled to the delay circuit for controlling the time delay of the delay circuit according to the frequency of its output, and normally oscillates at a relatively high frequency in the range of 80-100 KHz. A modulation signal generator is coupled to the carrier oscillator for frequency modulating the carrier oscillator toward lower oscillating frequencies, and a control signal generator is coupled between the input to the delay circuit and the modulation signal generator for detecting the musical tone signal input to the delay circuit and producing a control signal only when a musical tone signal input is detected.

Abstract: A device for electronically simulating vibrato, chorus, and pseudostereo effects and the radiation effects produced by a rotary loudspeaker with the aid of two loudspeakers or loudspeaker combinations, in which device a controllable amplifier is associated with each loudspeaker, the audio signal being applied to these amplifiers both directly and via a delay means, and both the delay and the gain of the amplifiers being varied synchronously by a subaudio-frequency generator.

Abstract: The specification discloses a pneumatic player piano which utilizes an electric motor roll drive. The roll drive is actuated by a mechanical switching arrangement which responds to the system vacuum so as to simulate the operation of a conventional air motor. The pneumatic stack is constructed to permit the pouch board and valve boxes of an entire level to be fabricated in a single molding operation. The valves themselves are formed of silicone rubber - and require neither backing, facing nor position adjustment.

Abstract: In an electronic musical instrument with two tone generators of which the frequency of the tones produced by them is substantially constant for the first generator a priori and for the second generator not until after a final value is reached which corresponds to the frequency of the corresponding tone of the first generator, the frequency of the first generator is applied to a first input and that of the second generator to a second input of a frequency comparator circuit, whose output is connected to a control input of the second generator via control device. This ensures that the repeated readjustments of the control quantities necessary in known instruments are no longer necessary.