Abstract: A musical tone generating device is capable of simulating various special playing techniques for a stringed instrument in which the harmonic spectrums of produced sound is enhanced, or otherwise altered. The device includes a delay circuit wherein an input signal thereto is delayed and output; a closed loop circuit comprising multiple feedback pathways to which the output of the delay circuit is supplied and processed therein, after which the processed signal is returned toward the delay circuit as an input signal; an excitation device in response to a predetermined control signal, generating an excitation signal and supplying it to the closed loop circuit, such that the excitation signal corresponds to an excitation vibration in the stringed instrument being simulated; and a control device wherein the predetermined control signal is generated and whereby the delay interval of the delay circuit and the processing carried out in the multiple feedback pathways are controlled.

Abstract: A musical tone synthesizing apparatus which is suitable for simulating and synthesizing the percussion instrument tone provides a closed-loop including at least an adder and a delay circuit. An input signal corresponding to a musical tone signal to be synthesized is supplied to the adder from an external device. The adder adds the input signal to its feedback signal. The output of adder is delayed by a delay time in the delay circuit, wherein delay time is controlled by a modulation signal. Then, delayed output of the delay circuit is fed back to the adder as the feedback signal. Thus, the output of adder or a signal propagating the delay circuit is picked up as a synthesized musical tone signal. Preferably, it is possible to provide a plurality of delay circuits.

Abstract: A musical tone waveform signal forming apparatus comprises a delay loop circuit, a filter circuit a drive signal generation circuit and a modulation control circuit. The drive signal generation circuit inputs a drive signal to the delay loop circuit so that a musical tone is formed in the delay loop circuit. The filter circuit filters the musical tone. The modulation control circuit changes the delay length of the delay loop circuit and the characteristics of the filter circuit thereby adding a modulation effect on the musical tone to be generated.

Abstract: A musical tone synthesizing apparatus comprising FM operators and connection control device. At least one of the FM operators comprises a waveform memory, phase data generation device, and output inversion device. The waveform memory stores fundamental waveform data. The phase data generation device generates phase data as an address signal for accessing the waveform memory on the basis of a musical tone designation signal and a modulation signal inputted from an external circuit. The output inversion device selects whether a waveform signal read out from the waveform memory is outputted after sign inversion, or is outputted directly. The connection control device arbitrarily combine connections of the FM operators.

Abstract: A tone generation system includes one or more digital waveguide networks coupled to one or more junctions, one of which receives a control signal for controlling tone generation. The control signal initiates and interacts with a wave signal propagating through the waveguide networks to form a tone signal. A non-linear junction may be employed which receives a signal from a waveguide, converts it in accordance with a non-linear function based upon the value of the control signal and provides it back to the waveguide. A tone signal whose pitch is determined by the wave transmission characteristics of the waveguide network is thereby produced.

Abstract: A pickup system for providing sounds for a musical instrument has a feedback circuit for converting a pickup signal representing a vibration of a string or other vibratory element to a drive signal. The pickup system includes a pickup coil, an electromagnetic source which generates a magnetic flux, a device such as a ferromagnetic element for magnetically linking the electromagnetic source and the pick up coil with the vibratory element, a step-up transformer having a primary coil section and secondary coil section, a connection between the pickup coil and the primary coil section of the step-up transformer, an output terminal and circuit elements for connecting the output terminal to the secondary coil section of the step-up transformer.

Abstract: A vibrator for vibrating an electronic musical instrument in accordance to the generated tone being produced. In this manner, a player of the electrical musical instrument will have the sensation of playing a conventional musical instrument due to the feedback of vibrational energy into the input device of the electronic musical instrument.

Abstract: A musical tone synthesizing device employing an operator, for generating musical tone signals by a modulation operation process. The device also employs a waveguide combined to the operator, for generating a reciprocating signal including a delay circuit for delaying the signal inputted into the waveguide feedback path, and for feeding back the output signal of the delay means to the signal, reciprocating within the waveguide.

Abstract: A musical tone synthesizing apparatus synthesizes musical tones by simulating the tone generation construction of a plucked-string or struck-string instrument. The apparatus has a loop circuit which simulates a vibrating element of the instrument, an excitation circuit creates an excitation signal corresponding to the excitation given to the vibrating element in response to the operation of operators such as a pick or a hammer or the state of the generation body and a memory which stores a non-linear relation between the operator and the vibration element. The excitation signal circulates around the loop circuit and is delayed by means of a delay circuit with a previously determined delay interval, and is fed back into the excitation circuit as the state of the vibrating element.

Abstract: A music synthesizer simulates the musical tones of bowed string and wind instruments. The synthesizer includes a noise generator which generates pulsed noise signals, as well as a resonant system or signal generator which generates deterministic or periodic signals. In one embodiment, the pulsed noise signals are combined with the periodic signals to generate an improved synthesized musical sound. In another embodiment, pulsed noise is added to an excitation signal for energizing a resonating system, which may or may not be dynamically coupled to the excitation generator, resulting in the generation of synthesized sound having appropriate noise characteristics for bowed string and wind instruments.

Abstract: A musical sound synthesizing apparatus which simulates a sound generating mechanism of a string instrument by using an electronic circuit comprises a driver for applying data, an adder, a delay unit for storing data temporarily, a low pass filter for processing data, and a word length designating unit for designating a word length (address width) of the delay unit. The adder, delay unit and low pass filter form a loop-shaped circuit, with their corresponding input ends and output ends connected with each other. The word length designating unit corrects a word length of the delay unit in accordance with a phase delay of the low pass filter or in accordance with the number of stages of the pipeline structure of the loop. In the case where a musical sound of the type generated by touching or hitting strings is synthesized, the driver reads at least two series of data stored beforehand and applies the read data to one of the inputs to the adder.

Abstract: A nonlinear function generation apparatus and a musical tone synthesis apparatus are disclosed.The nonlinear function generation apparatus comprises hysteresis and nonhysteresis function generators for generating hysteresis and nonhysteresis functions using an input signal as a variable respectively, and a multiplier for synthesizing the functions outputted from the generators.The musical tone synthesis apparatus comprises a closed loop including delay circuits, and the nonlinear function generation apparatus.

Abstract: A rhythm pattern generating apparatus is provided having a layered neural network to perform learning with feedback to generate an output pattern signal indicative of a musical sound pattern. The output pattern signal is generated by the layered neural network with feedback in response to a performance operation of a player. The layered neural network generates the output pattern signal indicative of the musical sound pattern based on both an input pattern signal and a weight signal. The output pattern signal is fed back by the feedback circuit to the layered neural network to perform the learning process. A drum pad can be used to provide an input to the rhythm pattern generating apparatus or, specifically, to gate an input pattern selector for selecting input pattern signals. The layered neural network with the feedback can perform the learning process using a back propagation method.

Abstract: A musical tone synthesizing apparatus has a closed-loop configuration including an adder, a filter and a delay circuit. The adder adds its feedback signal to a signal to be synthesized which is applied from an external device. The filter constructed as the all-pass filter has a frequency characteristic by which a phase delay between its input and output signals is varied in response to a frequency variation of its input signal. Such all-pass filter includes a delay element having a delay time which is set longer than a predetermined unit delay time corresponding to a sampling period to be employed. Herein, the output of adder is fed back to the adder via the all-pass filter and delay circuit as the feedback signal. Thus, a signal circulating the closed-loop is picked up as a synthesized musical tone signal.

Abstract: A musical tone synthesizing apparatus is disclosed wherein an excitation signal corresponding to performance data is generated and supplied to a loop circuit. In the loop circuit, this excitation signal is delayed for at least a fixed time period and a repeatedly circulating muscial tone signal is generated. At the beginning of the generation of this musical tone signal, a initial signal with a frequency which corresponds to the pitch of the generated musical tone is supplied. As a result of this, in the loop circuit, resonant operation is carried out quickly in accordance with the initial signal.

Abstract: A sustainer for providing sustained sounds from a musical instrument has a feedback circuit for converting a pickup signal representing a vibration of a string or other vibratory element to a drive signal and applying drive forces to the vibratory element responsive to the drive signal. The sustainer is arranged to compensate for the phase lag of the pickup signal relative to motion of the vibratory element and to compensate for the phase lag of the drive forces provided by the driver relative to the drive signal. The feedback circuit may be arranged to provide a phase difference between the drive signal and the pickup signal such that the phase difference varies with frequency towards a drive signal leading phase difference with increasing frequency. This phase compensation provides enhanced response of the strings in the fundamental mode of vibration. The driver preferably is arranged so that the drive forces applied to the strings do not vary with lateral movement of the strings.

Abstract: A musical tone waveform signal generating apparatus is used to generate the waveform signal full of variety which simulates the sound waveform of wind instrument. This apparatus provides a loop including first and second signal lines through which the waveform signal is circulated. Both of first and second signal lines are connected to a conversion portion which receives the waveform signal from the second signal line and a musical tone control signal which is used to control a musical parameter of a musical tone to be generated. The conversion portion effects the predetermined non-linear conversion on the waveform signal in response to the musical tone control signal so that a converted waveform signal to be obtained from the conversion portion is to be outputted to the first signal line.

Abstract: A melody generating system is fabricated from a switch unit operative to produce an activation signal, an analog signal producing unit responsive to the activation signal and producing an analog melody signal carrying pieces of melody information used for reproducing a melody and a sound unit responsive to the analog melody signal for reproducing the melody, wherein the analog signal producing unit comprises an analog signal producing circuit integrated on a single semiconductor chip and responsive to the activation signal for producing a read out controlling signal and a memory circuit storing the pieces of melody information and responsive to the read out controlling signal for producing a digital melody information carrying signal, and the analog signal producing circuit is further responsive to the digital melody information carrying signal for producing the analog melody signal, so that a system supplier easily copes with a request for a new melody by changing the pieces of melody information stored in t

Abstract: A musical tone signal generating apparatus provides at least plural modulation operation systems and plural memories, wherein each of the modulation operation systems carries out the predetermined modulation operation on each of plural pieces of input information applied thereto so that each of the memories stores the operation result thereof as the waveform information. These modulation operation systems are connected together such that plural pieces of waveform information stored in the memories are selectively supplied to each modulation operation system. By changing over the connections between the modulation operation systems and memories in the time-sharing system, the waveform operation is carried out based on the predetermined algorithms for forming the musical tone signal. Preferably, the predetermined modulation operation is the frequency-modulation operation.

Abstract: A sustaining device is provided for prolonging the vibration of a string of a stringed musical instrument having a first magnetic pickup means responsive to the vibration of the string. The sustaining device includes a magnetic string driver capable of inducing a vibration in the string. A first amplifier amplifies the output of the pickup to a level that provides sufficient energy to the driver to prolong the vibration of the string. A switch is coupled to the driver for selecting the mode of operation of the driver between the pickup mode of operation wherein the driver functions as a second magnetic pickup, and a driver mode of operation wherein the driver functions as a magnetic string driver. An output changing device is provided that is responsive to the switch for changing the output of at least one of the first pickup and a driver in response to a change in the mode of operation of the driver.

Abstract: The acoustic apparatus for generating a musical tone preferably adopts a speaker system utilizing a resonator constituted by a cavity and an acoustic mass for causing the cavity to acoustically communicate with an external region or a speaker system utilizing a back-loaded horn so that frequency characteristic is improved. In a musical instrument, including a resonator, like a guitar, all or part of a body is partitioned as the cavity, and acoustic mass such as a resonance port is disposed in the cavity as needed to set a desired resonance frequency. In a musical instrument having side plates or leg portions, the resonance port or the back-loaded horn is housed in the side plates or the leg portions.

Abstract: A vibrator for vibrating an electronic musical instrument in accordance to the generated tone being produced. In this manner, a player of the electrical musical instrument will have the sensation of playing a conventional musical instrument due to the feedback of vibrational energy into the input device of the electronic musical instrument.

Abstract: An electronic musical instrument having a plurality of operators for generating audio frequency waveforms and performing frequency modulation thereof. The operator comprises a wave generator, a phase generator, and an amplitude-envelope generator. The phase generator produces phase-angle data on the basis of frequency-number data modulated by ratio-of-frequency data. While the frequency-number data is common to all operators, ratio-of-frequency data varies independently of those applied to the other operators. This enables operators to create rich, dynamic, lifelike sound. One or more operators are provided with feedback loops that are capable of varying the amount of the feedback in response to key touch, etc., thus achieving expressive tone. A pitch-envelope generator is provided with a random-number generator which modulates the pitch envelope in a random manner to more closely simulate a performance on a real musical instrument.

Abstract: An electronic musical instrument of the digital synthesis type that uses digital processing techniques to impart not only the desired harmonic structure and pitch, but also to impart the correct amplitude and envelope. Only after all of the harmonic structure processing, all amplitude scaling, and all panning/mixing has been performed in digital circuitry, are the four outputs converted by digital to analog converters into analog musical outputs. Part of the digital processing includes a digital scaling circuit using a barrel interpolator to scale each sample from 1/2 to 31/32 and a shift right register to scale each sample between 1 and 1/32,768.

Abstract: A sustainer for providing sustained sounds from a musical instrument has a feedback circuit for converting a pickup signal representing a vibration of a string or other vibratory element to a drive signal and applying drive forces to the vibratory element responsive to the drive signal. The sustainer is arranged to compensate for the phase lag of the pickup signal relative to motion of the vibratory element and to compensate for the phase lag of the drive forces provided by the driver relative to the drive signal. The feedback circuit may be arranged to provide a phase difference between the drive signal and the pickup signal such that the phase difference varies with frequency towards a drive signal leading phase difference with increasing frequency. This phase compensation provides enhanced response of the strings in the fundamental mode of vibration. The driver preferably is arranged so that the drive forces applied to the strings do not vary with lateral movement of the strings.

Abstract: A sound effector for changing original sound signals generated from an electric musical instrument and picked up by a pickup element. The effector having an inductance circuit into aurally improved distinctive sounds by suitably distorting the waveform in a frequency band or original sound signals to be enhanced during amplification of the original sound signals. The sound effector includes a resonance circuit having a capacitor connected with the inductance circuit of the pickup element, an amplifier circuit composed of semiconductor elements for amplifying an output signal from the resonance circuit, a filter circuit for receiving the output signal from the amplifier circuit and for passing therethrough a signal having a predetermined frequency range, and a positive feedback circuit for positively feeding back a part of the signal passed through the filter circuit to the resonance circuit.

Abstract: A transducer for a musical instrument through which vibrations can be fed back to the instrument so that notes played on the instrument can be sustained. The transducer comprises a bracket for mounting the transducer to the instrument. First and second opposited permanent magnetic poles project away from the bracket. A first surface of a sheet of non-magnetic, non-electromagnetic resilient material is attached to the projecting first and second magnetic poles. An electromagnetic core has a spine and first and second legs originating at, and extending away from, the spine and terminating at first and second end faces, respectively. The first and second end faces are attached to a surface of the sheet opposite the surface of the sheet to which the permanent magnetic poles are attached, with the first face adjacent the first permanent magnetic pole and the second face adjacent the second permanent magnetic pole. A conductor is wound on the core.

Abstract: An input waveform signal is converted into a digital peak value signal by an A/D converter, and the digital peak value signal is input to one input terminal A of a comparator. The other input terminal B of the comparator receives a preset digital peak value signal from a memory. These input signals are compared by the comparator. The content of the memory is reduced at a predetermined rate. If the comparator detects that the currently input waveform level is larger than the continuously reduced level of the memory, i.e., if A>B, a new waveform level is loaded in the memory. As a result, the output from the comparator is inverted. That is, condition A>B is changed into condition A<B. The timing of this change in condition serves as a peak timing of the input waveform signal.

Abstract: An electronic musical instrument comprising a host processor (10), process/engine interface (12) and sound engine (14) the latter utilizing partial control chip modules (32, 34) and a data path chip module (36) to effect multiple partial (Fourier) synthesis, in conjunction with a sound modelling technique, to generate up to 240 independent partials and impress time-varying amplitude envelopes on them and select and apply them to sound generation, each partial being controlled by selected parameters of frequency, amplitude, phase and attack/decay rate. A modulo-sumdither and oversampling approach to noise reduction is utilized in connection with the data path chip arrangement. Log sine addition is utilized to avoid multiplication apparatus ordinarily required to combine sine wave defining parameters.

Abstract: A tone signal generating apparatus comprises a waveform memory in which a plurality of waveform data representing different waveforms but corresponding to a same tone name are stored. These different waveform data are sequentially read from the memory and are supplied to a digital low-pass filter which comprises a delay circuit and a multiplier connected to each other to form a feedback loop. The low-pass filter smoothes abrupt variation of the waveform data and outputs a smoothed waveform data thereby interpolating the different waveforms. A tone signal is produced in accordance with this smoothed waveform data.

Abstract: A musical tone signal generating apparatus generates a musical tone signal whose tone color can be changed independently of a pitch or a frequency of the musical tone signal. The musical tone signal generating apparatus comprises a shift register on which sampled data of a predetermined waveform are initially loaded. The sampled data in the shift register are shifted at a frequency corresponding to a rate of change of the tone color, and each sampled data shifted out of the shift register is subjected to a predetermined operation such as a multiplication by a predetermined coefficient and is fed back to the shift register. The sampled data in the stages of the shift register are selectively outputted by a selector controlled in accordance with selection control data formed based on the pitch of the musical tone so that the sampled data are outputted at a rate determined by the tone pitch. The musical tone signal is then formed based on the thus outputted sampled data.

Abstract: In a tone signal generation device, original waveshape amplitude data corresponding to a waveshape signal from an external source is stored in a first memory. Waveshape data is read out from this first memory and is properly modified by a tone processing circuit such as a filter or a modulation effect circuit. The modified waveshape data is reserved in a second memory. The waveshape data stored in the second memory is selectively transferred to the first memory. In this manner, the original waveshape data initially stored in the first memory can be freely modified and a tone can be produced with a high degree of freedom as in a music synthesizer.

Abstract: A digital system is provided for synthesizing individual voices of musical instruments, which may then be combined into a musical composition. The system for a single voice is comprised of means for solving a system of simultaneous finite difference equations, where time is represented by real time in the computations. Musical sounds of the voice can then be produced by repetitiously solving the difference equations that model the instrument in real time, using an array of elemental means named "universal processing elements" (UPEs) interconnected by a matrix to each other and to external input and output terminals, and varying the sounds by varying the parameters. Each UPE is capable of computing Y=A+(B.times.M) from pipelined bit-serial inputs. The difference equations model a general linear filter, a second-order linear filter, a nonlinear polynomial function, and a random number (noise) generating function.

Abstract: An electric stringed instrument such as a guitar having a sound reproducing element on the top of the neck for feeding the tones of the strings back into the guitar. (A sound reproducing element being a speaker or an electromagnetic transducer.) The tones of the strings are sent from the pickup to an amplifier and then to the sound reproducing element. This feedback will either prolong the note played or one of its harmonics or will not have any effect depending upon which note is played. Two wires are imbedded in the back of the neck to bring the electric signal to the sound reproducing element.

Abstract: A plurality of rhythm designation data are supplied from a CPU, and latched in corresponding individual latches which are responsive to channel data from a decoder. The latched data are supplied to an address ROM in response to corresponding channel timing signals, wherein start and end address data for a rhythm waveform data ROM are read out from the address ROM. If the rhythm designation data latched in one of the individual latches is the same as in another one of the latches, the same rhythm is sounded concurrently and without sound interruption.

Abstract: A first waveshape memory stores a full waveshape of a tone from the start to the end of sounding of the tone or a portion thereof in plural periods. A second waveshape memory stores waveshape data of a modification waveshape for the full waveshape or the portion thereof. A tone waveshape signal read out from the first waveshape memory and a modification waveshape signal read out from the second waveshape memory are both multiplied with respective coefficients whereby these waveshape signals are weighted. These weighted waveshape signals are added together to provide a mixed tone signal. By controlling the coefficients, the tone color imparted on the mixed signal is variously determined. The coefficients for the tone color control are provided in accordance with key scaling, key touch or operation states of control knobs. Thus, tone signals having a variety of tone color changes can be realized without the necessity of many wave memories.

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: In a musical tone synthesizer in which an amplitude-modulated carrier wave delivered from an amplitude modulator is used to form a musical tone signal, the amplitude-modulated carrier wave is fed back to the input side of the amplitude modulator as a modulation signal, a portion thereof, a portion of a carrier wave or a composite signal of the modulation signal and the carrier wave. The amount of feedback may be controlled by multiplying the amplitude-modulated carrier wave with a predetermined modulation index. Furthermore, the modulation index may be charged with time so that the control of spectrum construction of the musical tone signal is readily performed. According to a modified embodiment, a plurality of amplitude-modulators are provided which are connected in a ring form feedback loop in which the modulated outputs of preceding amplitude modulators are supplied respectively to succeeding amplitude modulators.

Abstract: The realism by which the sound produced by various musical instruments may be electronically simulated is enhanced by the storage of digital data commensurate with scanning values of several periods of a note including the release portion thereof. Command words are also memorized and, in response to the reading of a command word and the state of the input command to the instrument by the player, indicative of whether the note is to be sustained or terminated, the reading of a command word may cause the addressing of the waveform memory to be jumped to the release portion where the read-out will be continued from a scanning value approximately equal to the value read immediately prior to the reading of the command word. The waveform memory may contain a segment of the sustain portion of the note which will be repetitively read so long as the player's input command indicates that the note is to be sustained, the repetition also being in response to memorized command words.

Abstract: An operating member control device of an electronic musical instrument is constructed by a main unit and a plurality of subunits, each of which has a operating member for setting a musical tone element and a drive mechanism for moving the operating member. The main unit transmits in serial form a set of control data signals, which are preset in advance, designating desired target positions of the operating members respectively. The subunits further include serial to parallel converters, each of which receives the control data signals and serial-to-parallel converts the corresponding one of the control data signals. The operating members are moved from the current positions to the desired positions designated by the parallel converted control data signals respectively. By the construction as above, this operating member control device need a single line only with respect to the connection of the main unit and the subunits basically, thereby enabling simple wiring.

Abstract: An automatic rhythm performing apparatus capable of simultaneously producing a plurality of rhythmic tones having the optimum volume relationship irrespective of the total volume of the rhythmic tones. A plurality of rhythmic tone signal generating devices generate a plurality of rhythmic tone signals corresponding respectively to a plurality of rhythmic musical instruments. A combining device combines the rhythmic tone signals to provide a combined output signal as an output of this apparatus, the level of which can be varied by a signal level varying device. There are provided a detecting device for detecting the level of the combined output signal and a controlling device for separately controlling respective signal levels of the rhythmic tone signals in accordance with the detected level of the combined output signal, thereby making the volume relationship of the plurality of the rhythmic tones optimum.

Abstract: The present invention is a circuit for controlling the sampling of plurality of channels in an electronic organ having multiplexed keying. The channels having information signals at a particular time period is sensed and used to address a memory. The memory has stored a plurality of sequences of digital signals for controlling the multiplexing and demultiplexing operations of the organ. Only those channels containing information signals are sampled which accordingly increases the sampling rate which increases the frequency of the harmonic component of the square wave signals that can be passed by the system and the distortion caused by aliasing of harmonics is diminished.

Abstract: An electronic musical instrument is provided in which frequency signals are developed by voltage controlled oscillators which are controlled from an analog demultiplexer connected to a scanner of a keyboard and control circuit and in which envelope signals are developed by an envelope synthesizer in synchronized relation to the frequency signals, such frequency and envelope signals being applied to a waveform synthesizer circuit to develop output signals for production of tones. The keyboard and control circuit includes available oscillator and keyboard memories operable from a memory interchange circuit and further includes circuitry for accommodating overload, re-key and an optional portamento operation which is polyphonic in that the frequencies of a plurality of tones can be simultaneously and continuously changed. The circuitry also provides an infinite duration release capability.

Abstract: A musical instrument with a plurality of vibratile tone generators, whose oscillations are converted into alternating currents by electroacoustic transducers, is provided with a control circuit feeding back a regenerative vibratory signal of progressively diminishing amplitude to maintain the oscillations of a previously activated tone generator for a selected fade-out period. The duration of the fade-out period can be controlled by the player, e.g. with the aid of a pedal, by varying the time constant of a peak-storage network connected to the feedback loop. The feedback signal may be transmitted to the respective tone generator by a mechanical vibrator attached to the instrument body or by sound waves emitted from a loudspeaker. The player may also switch from the output of the peak-storage network to a constant control signal for sustained reverberation.

Abstract: A tone generation system intended primarily for use in electronic musical instruments wherein a digital representation of a harmonically rich waveform is sampled, and a musical tone is produced therefrom. The stored waveform could be the four term Blackman-Harris window function, which has negligible side lobes and thus greatly attenuated higher harmonics. The stored function is read out at a fixed rate, but the time periods between successive readings of the waveform are varied to thereby vary the frequency of the output signal.

Abstract: Apparatus for eliminating feedback in stage monitors for selected musical instruments includes filter networks for attenuation of a broad frequency range including the entire range of frequencies contributing to the feedback. A combination of high order low-pass and high-pass filters is used to pass fundamental and second order components of a selected instrument, while attenuating the undesired feedback frequencies as well as extremely low range frequencies capable of damaging a speaker. A pair of passbands is provided, and a pair of frequency bands is suppressed, the two pairs providing alternate attenuation and pass-bands. Active filters having operational amplifiers and frequency selective circuits are used, along with buffering and summing circuits, to attain the desired frequency characteristic.

Abstract: A tone generation system intended primarily for use in electronic musical instruments wherein a digital representation of a harmonically rich waveform is sampled, and a musical tone is produced therefrom. The stored waveform could be the four term Blackman-Harris window function, which has negligible side lobes and thus greatly attenuated higher harmonics. The stored function is read out at a fixed rate, but the time periods between successive readings of the waveform are varied to thereby vary the frequency of the output signal.

Abstract: A sliding formant effect is produced in a tone generator of the type in which wave shape data points are sequentially and repetitively read out of a memory at a rate corresponding to the fundamental pitch of a musical tone. The formant effect is obtained by forming the sums or differences between consecutive data points for one waveshape period and storing the new data in memory in response to a formant control signal. Provision is made for advancing or retarding the effective formant cut-off frequency under command of the formant control signal.

Abstract: An apparatus (10) for transforming digital data stored in a memory (18) into sounds is disclosed. The apparatus includes an oscillator (12) which drives an address selector (14). The address selector drives the memory. A note generator (20) generates an analog electrical signal responsive to the memory, and a speaker with its associated amplifier stages (22) produces sounds corresponding to the analog electrical signal.A preferred arrangement of the note generator includes an inverting amplifier which can simply be a logic gate (44) and a plurality of resistors (50) selected by switches (56) in feedback relationship with the amplifier.A preferred arrangement includes a duty cycle selector (80) to produce harmonics of the fundamental frequency of the analog electrical signal.

Abstract: A tempo control device for automatic performance according to this invention is of a type wherein a tempo of automatic performance is caused to automatically follow that of manual performance as the latter changes during performance. When difference in tempo between manual and automatic performance falls within a predetermined range, this automatic follow-up control is performed by measuring the manual performance tempo with accuracy and by controlling the frequency of tempo clock pulses in the automatic performance on the basis of the value thus measured. The predetermined range may be one fixed range for all notes of various note-lengths, or alternatively, different ranges may be employed in accordance with the length of notes.