Abstract: An electronic musical instrument comprises a plurality of musical tone forming systems capable of producing musical tones of different tone qualities. A priority is established between the respective musical tone forming systems and one which is of a highest priority among one or more such systems selected by a performer is automatically selected and a musical tone can be produced only from this selected system of the highest priority. The electronic musical instrument is capable also of producing musical tones from a plurality of predetermined systems simultaneously when the priority is rendered nonoperative thereby to produce an ensemble effect.

Abstract: An electronic musical instrument capable of producing a performance effect resembling arpeggio. Tones corresponding to one or more depressed keys are sequentially produced from the lowest tone or the highest tone and an octave range in which tones are produced is shifted toward a higher octave or a lower octave at completion of each cycle of the tone production sequence. This shift of octave is continued to a certain predetermined octave and, after the tone production in the predetermined last octave has been completed, the tone production is repeated from the original octave or the tone production is conducted with the octave range being shifted in a reverse direction.For realizing simulation of arpeggio, plural key information produced by depressing a plurality of keys needs to be selected in a predetermined sequence. To this end, an up-down counter is employed in an example of the present invention.

Abstract: An electronic reverberation device comprising an input amplifier and an output amplifier connected in a circuit in which a delay device is connected between an output of the input amplifier and an input of the output amplifier, and a feedback path connects an output of the output amplifier to an input of the input amplifier. In order to render the operation of the device substantially frequency-independent, the delay line is a variable delay line the delay of which can be regulated by a regulator controlled by a control device which derives a control voltage from the output of the input amplifier. Preferably, the delay device is a bucket memory, the regulator a clock, and the control device comprises a diode having one terminal connected to the output of the input amplifier and another that is earth-connected through a capacitor and connected through a resistor to a control input of the clock.

Abstract: An organ performance supporting device which has means for detecting ON signals of actuating switches of combination units to provide control code signals, means for setting signals indicating the individual operative states of the switches by the switch-ON detecting signals, a read-only memory for storing coded control signals necessary for the presetting and selection of registrations, the coded control signals being selectively read out in reply to the detected control code signals, a combination registration memory composed of a writable memory and a read-only memory, the combination registration memory storing registrations required by the combination unit and selectively read out in reply to the detected control code signals, a register supplied with a signal from a stop switch and reading out the writable and read-only memories in a predetermined operative state to store the state of the combination unit and the ON-OFF state of the stop switch, a register for storing the registration output from each c

Abstract: Disclosed is a digital arpeggio system for an electronic organ that through the use of digital techniques permits arpeggios, note sequences as well as strum, multi, organ, and normal modes of operation to be played automatically. Two counters scan by counting through an 8.times.8 matrix of 64 words covering the 61 notes of an organ in rapid sequence upon the playing of one or more organ keys. Each word is fed to a corresponding one of 61 decoders, one for each note of the keyboard. If a corresponding key has been played, the decoder provides a signal to a corresponding pulser circuit which enables a corresponding keyer to transmit an audio signal from an audio oscillator corresponding to the played key to an output system and loudspeaker. The two counters are stopped by a clock control while the note is sounded and then the counters are enabled by the counter control to continue counting through the matrix until the next actuated key is located.

Abstract: An envelope waveform generating apparatus comprising a key code generating device composed of a means for releasing key code data and a means for outputting first and second control signals, a key assignor composed of a means for outputting a third control signal, a level setting means, and a function generator. The envelope waveform generating circuit is provided with a touch response so that the level of envelope waveform may readily be set.

Abstract: A rhythm pattern variation device which has an address counter for generating a memory read-out address signal in accordance with a rhythm clock, a memory for outputting a prestored rhythm pattern in accordance with the address signal, means for selectively branching the outputted rhythm pattern to two lines, a variation circuit for producing a rhythm pattern of a desired time lag from the rhythm pattern on one of the two line, and means for combining the rhythm pattern on the other line and the delayed rhythm pattern from the variation circuit into a composition rhythm.

Abstract: Disclosed is a digital arpeggio system for an electronic organ that through the use of digital techniques permits arpeggios, note sequences as well as strum, multi, organ, and normal modes of operation to be played automatically. Two counters scan by counting through an 8.times.8 matrix of 64 words covering the 61 notes of an organ in rapid sequence upon the playing of one or more organ keys. Each word is fed to a corresponding one of 61 decoders, one for each note of the keyboard. If a corresponding key has been played, the decoder provides a signal to a corresponding pulser circuit which enable a corresponding keyer to transmit an audio signal from an audio oscillator corresponding to the played key to an output system and loudspeaker. The two counters are stopped by a clock control while the note is sounded and then the counters are enabled by the counter control to continue counting through the matrix until the next actuated key is located.

Abstract: A keyboard operated tone synthesizer with glissando effect in which actuating individual keys successively on a keyboard produces all the intermediate notes of the chromatic scale. The time interval between notes in the scale is independently controllable. In one modification of the invention the individual notes of the chromatic scale played during the glissando, when played slowly enough to be heard individually, can be controlled in attack, decay, sustain and release characteristics. The chromatic glissando can move either up or down the scale, depending upon the pitch of each key relative to the previous key played on the keyboard.

Abstract: The inventive circuitry extends the harmonic content of musical tones produced by a computor organ of the type disclosed in U.S. Pat. No. 3,809,786. A memory stores values of an algebraic approximation of the summation of the amplitudes of a set of Fourier components of order higher than those separately evaluated by the computor organ itself. As each musical waveshape sample point amplitude is computed by the computor organ, the stored summation approximation value for the corresponding sample point is accessed from the memory. This accessed value is appropriately scaled, and is added to the sum of the lower order Fourier component contributions that are calculated by the computor organ. The resultant sample point amplitudes are converted to musical tones in real time. In an illustrative embodiment, musical tones having the spectral content of a sawtooth wave are produced.

Abstract: Imitation sounds of musical instruments, especially brass wind instruments, re synthesized by using a pulse generator source driving an AGC amplifier channel having an AGC amplifier and formant filters and a limiter, the gain of the AGC amplifier being multiplicatively controlled by an instantaneously-varying control AGC signal derived from the output of the channel. The AGC signal can also be varied at the AGC point by the signal from a breath-sensing microphone in a whistle or pipe.

Abstract: A manually played electrical musical instrument of the electronic type in which simultaneously with selection and playing of a melody tone (note) a predetermined pattern of harmonies are also selected in such manner that at least five of the harmonies selected for the appertaining tone are mutually different. The instrument also includes generation of rhythm sound effects which permits programming of predetermined rhythm patterns defining the times of occurrence of predetermined rhythm sounds in a sequence of a predetermined number of beats, and generation of different bass tones according to a sequence of notes.

Abstract: An electronic musical instrument incorporates a single integrated circuit chip for performing a variety of logical operations for the production of chords and various accompaniment signals automatically, in response to depression of one or two keys within a related portion of the keyboard of the instrument. A multiplexer is employed, in association with the keyboard, to produce a train of signals in response to depression of one or more keys, and one or more function control switches; certain ones of these signals are used to address a plurality of read only memory devices for the generation of the several components needed for the mode of operation which is selected. In an automatic chord mode, a chord is selected automatically, corresponding to an operated key of the keyboard. The chord components include the root, the third (which may be selectively minored), the fifth, the sixth and the seventh (which can be selected or not).

Abstract: The electronic musical instrument is provided with a musical tone signal generating unit for generating a musical tone signal having a tone pitch corresponding to a depressed key, a self-running counter for counting a multibit digital quantity, a latch circuit for latching the output of the counter when supplied with a pulse signal representing the depression of a key, and modifying means responsive to the output of the latch circuit for modifying the musical tone elements, that is the pitch, color and volume of the musical tone signal generated by the musical tone signal generating unit.

Abstract: Improved apparatus for use in an electronic musical instrument having a keyboard including a group of keys corresponding to the notes of a musical scale. Electronic circuitry is used to generate simultaneously with respect to each of the keys first and second electrical tone signals. The circuitry causes the waveshapes of the tone signals to deviate with respect to each other. In addition, the repetition rates of the tone signals are detuned and frequency modulated with respect to each other so that the sound of a string chorus is simulated.The disclosure also describes circuitry useful in an electronic musical instrument having a keyboard including twelve keys corresponding to the twelve notes of a chromatic musical scale. The circuitry generates simultaneously a first series of twelve tone signals corresponding to a first tempered scale and a second series of twelve tone signals corresponding to a second tempered scale different from the first tempered scale.

Abstract: A sustained repeat control in a digital polyphonic synthesizer for gradually decreasing the amplitude of one or more notes generated repetitively in response to operation of a single key. The sustained repeat control includes a digital register storing a plurality of control words in digitally coded form, there being one control word assigned to each note being generated at any one time. Each word includes bits coded to indicate the current relative amplitude of the associated note. When a key is depressd, the control word or words for the note or notes assigned to that key have bits initialized to a predetermined value. When the key is released the amplitude values represented by the bits are counted down periodically. The bits in turn control the amplitude of the repetitively generated notes, a zero detector terminating the operation when the bits are decremented to zero.

Abstract: A choral generator is formed from a plurality of delay channels, each including a modulated delay line which non-linearly varies the time delay imparted to a signal passing through it. The outputs of the delay channels are combined with the undelayed audio signal to form a composite output characterized by enhanced musical presence.

Abstract: An amplitude curve generator for use with an electronic organ or the like to control the musical shape of an audible tone. The generator utilizes a simple binary down counter driven from a clock source to produce a sequence of decreasing binary numbers that approximate the relative amplitudes of equally spaced points along an exponential decay curve. The count condition of the least significant bits of the counter correspond to the mantissa of number expressed in binary floating point notation. The most significant bits represent the power. The bits of the mantissa are transferred to a parallel shift circuit and shifted a number of times determined by the bits of the power to convert the number in the counter to fixed point notation. The output of the shift circuit is used to control the envelope amplitude of a musical tone. The output may be subtracted from one (2's complement) to produce a set of values that correspond to an exponential attack curve rather than a decay curve.

Abstract: This invention relates to an electronic musical instrument which comprises a waveshape computation cycle, a waveshape transmission cycle and an envelope load output. In the waveshape computation cycle, a musical waveshape is obtained in the form of the accumulation of the products of the nth powers of the fundamental frequency of a cosine wave and coefficients A.sub.n indicating harmonic components of a musical note in certain relationship.

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.

Abstract: An envelope circuit for a keyboard type electronic musical instrument having a damping and sustain characteristic. The circuit has a keyswitch operated in association with the actuation of a key on the keyboard of the electronic musical instrument to connect a power supply to a voltage responsive circuit for producing a decreasing volume output tone. A sustain circuit is coupled to the voltage responsive circuit for sustaining the operation of the voltage responsive circuit and is connected through a blocking diode to a sustain switch common to all the envelope circuits in the musical instrument. The sustain switch is connected in the sustain circuit for bypassing the voltage supplied thereto from a time constant circuit when the sustain switch is closed for making the sustain circuit inoperative to deenergize the voltage responsive circuit, whereby the voltage responsive circuit continues to produce an output tone independently of how the keyswitch is restored to its initial position.

Abstract: In order to simplify the intricate wiring in known automatic bass chord systems and to reduce the number of separate decoders used therein for all chords of each key, an apparatus is provided which allows the use of only one decoder per chord type. When a chord is held one bit is applied to the inputs of a first 12-bit shaft register which correspond to the tones of the chord, after which all bits are shifted further by an HF clock pulse until this chord pattern has arrived at those outputs of the 12-bit shift register which, with the inputs of the decoder which corresponds to the chord being held, are assigned to a single pre-selected tonality.

Abstract: Keyboard apparatus for an electronic musical instrument in which a particular code is assigned to each of keys of the keyboard and which is provided with a multiplexer circuit for detecting the depression of the key corresponding to an input code, means for sequentially generating the codes of the keys, memory means for storing the codes, a comparator circuit for comparing the outputs from the memory means and the code generating means to provide a coincidence signal when the both outputs are coincident with each other, a cycle control circuit for controlling a key ON cycle and a key OFF cycle in distinction from each other, and gate means for selecting the output code from the code generating means and the code of the memory means with the key ON cycle and the key OFF cycle to output to the multiplexer circuit. In the key ON cycle, the multiplexer circuit detects that the key having not been depressed yet is newly depressed, and stores it in the memory means.

Abstract: In a chopper keyer electronic organ system, a sampling network samples the drawbar inputs to the chopper keyers in order to provide a separate channel of percussion. The drawbar lines for one or more of the footages are sampled and the sample signal is amplified and shaped to provide touch envelope percussion in addition to the sounding of the chopper keyer outputs. Alternatively, the chopper keyer outputs may be disabled and separate voicing such as for piano, harpsichord or steady tones provided via the drawbar sampling circuitry.

Abstract: A key assignor comprising a scanning means, a first clock memory, a second memory for releasing a switch information, a comparator, a priority circuit device, a means for inhibiting the write-in operation, and a means for extracting key codes. Key switches are divided into blocks to scan the latter without scanning all of key switches. Scanning time can considerably be reduced as compared to prior arts, thereby enhancing response greatly.

Abstract: A key code generator for electronic musical instruments which has a switch matrix circuit having a plurality of switches disposed at the intersections of two sets of buses, means for simultaneously applying signals to the switch matrix circuit from one of the two sets of buses to derive outputs from a plurality of blocks into which the buses of the other set are divided line by line, a memory for detecting the blocks that even one switch is in the on state from the bus outputs of the switch matrix circuit and temporarily storing signals of the detected blocks, a first priority selector for selecting block signals in a predetermined order of priority from the bus outputs and sequentially outputting the block signals with a predetermined clock pulse, means for inhibiting the block detecting operation during outputting from the first priority selector and applying the selected block signals to the buses of the detected blocks to sequentially scan only the detected blocks, a second priority selector for selecting

Abstract: An arpeggiator for an electronic organ, comprising a source of ramp voltage having selectively a slowly ascending and a slowly descending section or only a slowly ascending section followed by a rapid reset, an accordion-like voltage divider for said ramp voltage consisting of a cascade of diodes, each calling forth one of a group of three tone signals when conductive, or no tone signal if short circuited, circuits for determining which diodes shall be conductive and which short circuited according to which keys of an organ are actuated, the ramp voltage peaking when all conductive diodes have been ascendingly scanned by the ramp voltage, each conductive diode when scanned by the ramp voltage falling forth a gating signal for one of the tone signals called for by the actuated keys, in orderly sequence of tone signals.

Abstract: Two sets of digital tone generators are provided for a musical instrument. The members of the first set of generators create data which represent discrete amplitudes of a musical waveshape corresponding in the time domain to be true musical frequencies played by the musician. The members of the second set of generators create data which represent discrete amplitudes of a different waveshape corresponding in the time domain to frequencies which in general are note selected as true musical frequencies. Provision is made for multiplying the data created by selecting pairs of digital tone generators, one from each of the two sets. The resulting modulated data is converted into analog signals in a form suitable for a conventional sound system.

Abstract: There is disclosed a circuit for controlling the expression of an electronically controlled keyboard instrument and is an improvement on the circuit disclosed in application Ser. No. 680,996. The circuit works on the principle that by switching a solenoid on and off at a rapid rate and then varying the time on versus the time off, the energy supplied to the solenoid varies and therefore the striking force of the piano is changed. In accordance with the present invention, precise control over the width of the pulses is achieved by first setting a set voltage level and then adding thereto increments of set voltage according to a binary weighting. These voltages are then added and compared with a triangular voltage in a comparator. Both the up ramp portion and the down ramp portion of the triangular waveform are utilized and compared against the sum voltages. The pulse width of the comparator output is thus a function of the intersection of the ramp voltage, both up and down ramps, with the sum voltage.

Abstract: Spatially separated high frequency tonal effects from an electronic musical instrument having less tone generators than keys selectable. A high frequency speaker system is provided in addition to the normal audio system. The audio signals produced by the tone generator are applied to a high pass filter-amplifier circuit before application to a tweeter switch. Digital logic is provided to demultiplex the note generator capture signal for note generator assignment information. The demultiplexer information is applied to the tweeter switches to effect the activation of a tweeter switch and permit the sounding of the tweeter speaker. Thus it may be seen that the present invention permits the separate soundings of the high frequency range in a directional fashion, creating the movement of sound sources and changing spatial relationships in response to key activity.

Abstract: In an electronic musical instrument a demultiplexing audio waveshape generator, which accepts multiplexed frequency signals and generates a complex audio waveshape. This is accomplished by having a multiplexed frequency source with one or more outputs with each output being individually connected to a weighted resistor. The outputs of the resistors are connected in common to create a current source for presentation to an analog switch. The analog switch selects the multiplexed channels to be combined to produce the audio output signal, and through the use of gating signals can be made to create pulsed waveshapes. In the preferred embodiment of the present invention the signal from the analog switch is presented to a capacitance-resistance combination. The switched current presented to the capacitor causes an incremental charging and discharging of the capacitor which corresponds to the desired contribution of that particular channel to the audio output signal.

Abstract: A waveshape memory type electronic musical instrument produces a tone signal by cyclically reading wave value samples of a tone waveshape stored in a waveshape memory. The electronic musical instrument comprises a function generator for generating a periodic function signal which includes the mathematical product of an amplitude term varying as a function of time and a cyclic term of a selected frequency, and a multiplier for modulating a part of the tone waveshape by the periodic function signal, thereby producing a musical tone signal changing in waveshape as time lapses.

Abstract: An electronic musical instrument capable of producing an attack repeat effect. The attack repeat effect is a musical effect produced by repeated occurrences of attack and decay during a single continued sounding of a musical tone, giving to an audience an impression as if the tone started and stopped repeatedly. According to the invention, a complete envelope shape starting by an attack portion and ending by a decay portion is stored in a memory. When a key on the keyboard is depressed, the stored envelope shape is read from the memory and, upon completion of reading of one cycle of the envelope shape, reading of the envelope shape is resumed from the beginning. A time division multiplexed reading out of the envelope shape is conducted with respect to a plurality of channels. The read out envelope shape is used for controlling the amplitude of the musical tone signal. If the key is released, reading of the envelope shape is no longer repeated for a next and subsequent cycles.

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: An electronic musical instrument has a plurality of tone selectors which select musical tones; a waveshape calculator which calculates a waveshape represented by amplitudes at two or more than two sampled points of one period of the selected tone and which is operative whenever the tone selectors are actuated; a plurality of waveshape memories which temporarily memorize the calculated waveshapes; clock signal generator which generates clock signals with high frequencies corresponding to pitches of depressed keyswitches of the musical instrument and which is operative whenever the keyswitches are depressed; a reading circuit which repetitively and successively reads out the memorized waveshape amplitudes by the clock signal generated by the clock signal generator; and a converter which converts the waveshape amplitudes read out by the reading circuit to a musical tone, wherein a musical tone is generated by repetitively reading out the temporarily memorized musical waveshape.

Abstract: A pedal tone generator for an electronic musical instrument, such as an electronic organ, having the capability of automatically producing bass rhythm patterns based on a tonic note, includes a memory for storing a plurality of rhythm patterns which has a plurality of outputs for producing a predetermined pattern sequence for each of the notes of the diatonic musical scale, and a circuit for producing signals indicative of which of the pedal keys, usually thirteen, is operated by the instrumentalist. The pedal key signals are binary encoded to produce a plurality of code words each unique to the tone of one of the keys, and each of the outputs from the memory is also binary encoded to be uniquely represented by one of a corresponding number of code words. Code words representing a depressed key and the note instantaneouly being "played" by the memory are added to produce a coded digital signal representative of the sum in the duodecimal system of counting.

Abstract: An electronic echo apparatus comprising an input amplifier, an output amplifier connected thereto through a transmission channel, a delay device connected in parallel to said channel, and a feedback path connected in parallel to said delay device, characterized in that said feedback path includes a control means, and in that there is connected to the output of the output amplifier a means for measuring the output signal of said output amplifier, comparing said output signal to a predetermined threshold value and, when said output signal reaches said threshold value, supplying a control signal to said control means for terminating the feedback.

Abstract: The hand-held instrument is preferably supported by a strap from the neck for one or two handed playing of a keyboard with switch and potentiometer controls of a remote synthesizer which may be basically of conventional design and include a plurality of output voice means. A lightweight keyboard assembly is mounted within an elongated premolded housing having a control panel comprised of control switches and light indicators. The instrument is preferably for playing by the right hand, and for the purpose of holding and controlling the stability of the instrument, the housing is formed with a left hand gripping hole or slot permitting the instrument to be firmly gripped. Adjacent the hole there are provided additional control knobs and push button switches which are easily operated by the left hand without any repositioning of the hand. An umbilical cord interconnects the hand supported keyboard musical instrument and the synthesizer apparatus.

Abstract: In a digital type electronic musical instrument, a glide effect is produced by digitally frequency-modulating the frequency of a musical tone in such a manner that the frequency changes quickly and smoothly. Glide information used for effecting this frequency-modulation is produced on the basis of a glide code obtained by counting a clock pulse. The glide information which changes its contents uniformly is multiplied with the basic frequency information to effect the frequency-modulation. The glide effect can be controlled for each individual keyboard. According to an embodiment of the invention, the frequency-modulation is applied to an attack portion of a musical tone only and sustain and decay portions of the musical tone are reproduced with a normal frequency so that the musical tone will be provided with a crisp, vivid musical effect.

Abstract: Simultaneously played notes on a keyboard are automatically provided with different voice timbres. The assignment of voices to notes is by relative frequency-scale position within the chord. If four or more notes are played, the notes are scanned along the musical scale and the three lowest notes played and the highest note are sounded in different voices with the solo voice assigned to the highest note. Assignment of voices occurs automatically when fewer than four keys are played. One form of the system combines time multiplexed keying with priority coupling of the keying information to a plurality of voltage controlled oscillators through sample-and-hold memory circuits. Each oscillator has its own tone voicing circuits. In another preferred all-digital embodiment, the time division multiplex digital logic signals representative of the played keys are applied instead to a memory circuit and a comparator circuit.

Abstract: Musical notes having time variant modification of the waveshape are produced polyphonically in a tone synthesizer by computing master and transient data sets, transferring these data to buffer memories, adding the data read out from the buffer memories briefly during a transient time interval and repetitively converting the summed data to waveforms. The master and transient data set are created repetitively and independently of tone generation by computing a generalized Fourier algorithm using stored sets of generalized Fourier coefficients. Circuitry is disclosed for independently applying Attack/Release modulations to the principal tone generated from the master data set and to the transient tone generated from the transient data set.

Abstract: An electronic musical instrument comprises a plurality of tone generators for independently producing tone signals having slightly different frequencies, though fundamentally corresponding to the note of a key depressed on a keyboard; and a mixing circuit coupled to the outputs of the tone generators. The respective tone generators are provided with a control input and are brought to start in the same phase in response to application of an initial synchronizing pulse to the control inputs, thereby attaining clear rise of musical sounds immediately upon key depression. The synchronizing pulse may be produced necessarily at the instant of key depression only when an output of the mixing circuit has a amplitude level lower than a predetermined level.

Abstract: For reiteration of percussive sounds in an electronic organ there is provided a circuit for generating pulse signals for reiteration control which are "on" for much longer periods than they are "off", thereby substantially reducing the chance of an organ key being actuated when the control signal is in its "off" condition. The circuit is so arranged that playing of an additional key at a time when one or more other keys are being held has no effect on the reiteration of the sound produced by the held keys. The circuit generates four control signals which are connected such that each controls three notes in a given octave on the keyboard, a different three in successive octaves, such that when normal intervals (e.g., thirds, fourths and fifths) are played, the effect of random reiteration control is produced.

Abstract: A reverberation apparatus is adapted for mechanical matching characteristics and comprises at least one reverberation unit comprising a plurality of lattice construction systems of coil springs for transmitting sound-frequency mechanical vibrations, each spring system of which is connected to an electro-mechanical driver transducer and to a mechanical electrical pick-up transducer. Each system of coil springs forms parts of a lattice in at least two dimensions and in the system, the coil springs are mechanically interconnected at a number of coupling points. In each system of coil springs at least some of the coil springs are connected to a rigid frame.

Abstract: A digital musical instrument incorporating the effects of attack and decay by appropriately scaling the digitally synthesized waveform information at the leading and trailing portions of the waveform envelope. Such an instrument would be capable of producing two attack and decay periods with only one attack and one decay period resulting in the normal audible effect. The system is particularly adapted for use in an electronic musical instrument in which a digital multiplexed signal is generated by actuation of the keys of the instrument. The attack and decay periods generated by actuation and deactuation of the keys are processed such that each period is divided into "n" scale factors spaced in time, each such scale factor being associated with a different level of the waveform envelope. The scale factors cover the range of waveform envelope from zero to full scale. Upon receipt of a clear pulse, the digital counter begins counting, and would terminate the count upon reaching "n".

Abstract: An arrangement for forming a musical chord signal in which there are provided a frequency divider for root, a frequency divider for minor third, a frequency divider for major third and a frequency divider for fifth or a frequency divider for seventh. These are connected in common and to an input terminal of a tone source signal. The frequency divider for minor third and the frequency divider for major third have a selection circuit for selectively taking out an output signal according to a major chord or a minor chord of music. The input terminal is connected through plural key-switches to the plural tone source signal oscillators. The output terminals of the frequency divider for root, the selective circuit and the frequency divider for fifth or the frequency divider for seventh are connected together through respective gate circuits which are opened and closed by an output pulse signal of a rhythm pulse generator.

Abstract: In a digital tone synthesizer, musical tones are created by evaluating a generalized Fourier transform of harmonic coefficients. Tones corresponding to pulse-like waveshapes are simulated by using harmonic coefficient values associated with a pulse waveshape of specified shape. Apparatus is disclosed for producing sets of such harmonic coefficient values wherein each particular set is associated with a selected value of a pulse width parameter. Pulse width modulation tonal effects are achieved by changing the value of the pulse width parameter as a function of time. Means are described for including pulse width modulation as a subsystem of digital tone generators.

Abstract: Method and apparatus for securing vibrato and tremolo effects in musical instruments, such as electronic organs, wherein an incoming electrical signal is separated into high and low frequency components which are injected into opposite ends of a multiple-tap delay line. Analog multiplexers are connected to the line and are addressed to scan the delay line terminals sequentially in both directions. In a preferred embodiment, the duty cycles of high frequency sampling signals connected to enable the output of each multiplexer are modulated to secure a smooth transition in a composite output signal between the signals appearing at successive delay line terminals. Alternative methods and apparatus for blending successively scanned delay line signals are also disclosed.

Abstract: A musical ensemble effect results when two tones slightly out-of-tune with respect to each other are sounded together upon selection of a single instrument key. Herein, apparatus is disclosed for producing an ensemble effect in a polyphonic tone synthesizer of the type wherein musical notes are produced polyphonically by computing a master data set, transferring data set to buffer memories, and repetitively converting in real time contents of memories to notes. A multiplicity of master data sets are created repetitively and independently of tone generation by computing a generalized Fourier algorithm using stored sets of generalized Fourier coefficients. The phase of such master data sets are generated with time varying phase shifts to provide theout-of-tune ensemble effects. The phase shifted master data sets are combined and transferred to buffer memories from which such data is converted to musical sounds.

Abstract: In an electronic musical instrument a key touch signal is generated in response to the operation of a key, and a plurality of control signals having different waveforms are produced from the key touch signal.Different control signals are used for independently controlling at least two of a plurality of musical tone elements that determine the tone pitch, color and volume of the musical tone generated by the musical instrument.