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

Abstract: A wave-shape generator advantageously used for generation of various wave-shape signals on electronic musical instruments comprises, as a substitute for multiple wave-shape memories needed in the conventional wave-shape generators, a combination of a single wave-shape memory with a weighting parameter signal generator. Modulation of the wave-shape signals via multiplication by corresponding weighting parameter signals enables formation of a wide variety of different wave-shape signals without enlargement in construction, the wave-shape signals being changeable even in a time-functional fashion too.

Abstract: A keying system in an electrocin musical instrument comprises a circuit for generating harmonic level control voltages for controlling the levels respectively of harmonics (inclusive of the first harmonic, i.e.

Abstract: A multiple pitch generator, in particular a chime generator, incorporated in an electronic organ of the multiplexed variety wherein the keyboard is scanned and a cyclically recurring serial data stream produced wherein keydown pulses appear in time slots corresponding to depressed keys of the keyboard. The chime generator produces a plurality of tones in response to the actuation of a single key of the solo keyboard, for example, wherein the tones are those necessary to closely simulate a chime sound. This is accomplished by sequentially passing the serial data stream containing the keydown pulse through a series of shift registers which insert in the data stream pulses in subsequent time slots corresponding to the next three lowest tones making up the chime.

Abstract: A musical tone varying in tone color with the lapse of time is produced in an electronic musical instrument by retrieving a plurality of different waveshapes from a plurality of memories and then by mixing these retrieved waveshapes at a variable ratio according to a plurality of time-dependent parameters. In order to ensure a simpler arrangement of the instrument while maintaining richness in tone color variation characteristics of the produced musical tone, the mixing is adapted to be performed by carrying out multiplications individually on the respective retrieved waveshapes with the associated time-dependent parameters and then by adding up the resultant values to obtain the aimed musical tone. Some of the time-dependent parameters may be derived from other time-dependent parameter in the mixing procedure of several different waveshapes.

Abstract: An electronic musical instrument is of a waveshape memory read out type which includes a waveshape memory device for storing amplitude values at respective sampling points in one period of a new musical tone waveshape to be generated subsequent to a present musical tone waveshape stored in another waveshape memory device, first calculating means for calculating differences in amplitude values at respective sampling points stored in corresponding addresses of the two waveshape memory devices respectively; renewal rate control means for generating a waveshape renewal signal having a period corresponding to difference information produced by the first calculating means, and renewal means for effecting renewal of the memory content of said another waveshape memory device at a rate corresponding to the period of the waveshape renewal signal.

Abstract: A plurality of rectangular waves of selected duty cycles and fundamental frequencies are generated. Selected ones of these waveforms are then added at selected amplitude ratios. Such additions provide resultant waveforms of desired fundamental frequencies and having desired harmonic contents or spectra, for simulating the characteristic sounds of acoustical musical instruments.

Abstract: An electronic tone generator of a type in which an audio signal of controlled waveform is generated from a stored master data list of digitally coded words incorporates apparatus for changing the harmonic structure of the waveform with time during the generation of the audio signal. The master data list is computed by generating two data lists of words defining different waveforms and multiplying the two lists together repeatedly while shifting one list relative to the other list by at least one word. The resulting master data list changes with each multiplication following a shift, producing a changing waveform in which the musical frequencies are harmonically related, the waveshape being free of intermodulation distortion.

Abstract: There are provided a plurality of key switches which respectively designate the pitches of the musical tones to be generated, a frequency number generator which generates frequency numbers corresponding to the respective key switches, a harmonic order number generator which generates harmonic order numbers representing the orders of the respective harmonic components, an arithmetic processor for producing a multiplication product of the frequency number and the harmonic order number, an accumulator which repeatedly accumulates the output of the arithmetic processor of each harmonic order at a predetermined speed, and a sinusoid table including a memory device storing the amplitude values at respective sampling points of a sinusoidal wave for generating the amplitude values of the sinusoidal wave corresponding to respective harmonic components thereby producing the harmonic components.

Abstract: An electronic musical instrument is provided with a plurality of wave shape memories storing different musical tone wave shapes of different memory sizes for different tone ranges. The memory for the treble tone is of a small size and that for the bass tone is of a large large size. When a key is operated in the keyboard, a memory corresponding to the tone range to which the operated key belongs is selected and read out. While successfully avoiding economically disadvantageous increase in the memory size of the wave shape memories, beautiful and clear musical tones can be obtained having different tone colors for different tonal pitches just like those generated by natural musical instruments.

Abstract: A keyboard for a monophonic musical instrument has a plurality of touch sensitive keys which function as variable capacitors, the capacitance depending on the force applied to the keys. The variable capacitance is detected and used to produce a variable control voltage which is used to execute one or several of various control functions, such as controlling the volume of the sound produced by The instrument, controlling the cutoff frequency of a low pass filter in the output system of the instrument, controlling the amount of vibrato or other periodic modulation introduced into the sounds produced by the instrument, controlling the frequency of the vibrato or other periodic modulation, or controlling the amount of "bend" in the pitch of a sound produced by the instrument, i.e. shifting the pitch slightly from its nominal value. The variable capacitors employ a conductive elastomer which is deformed in response to the force applied to the keys.

Abstract: A polyphonic tone synthesizer in which two or more distinct voices are sounded by operation of a single key. While the voices have the same fundamental frequency, they are made audibly distinct by differing in harmonic content and differing in the shape of the envelope of the voice signal. The two or more voices are synthesized by alternately calculating master data lists of the amplitude values representative of points on the waveforms of the two voices, adding the two master data lists and converting the resulting values to an analog waveform by feeding the data to a digital-to-analog converter at a rate determined by the fundamental frequency of the note. The master data list for each voice is calculated repetitively during the time the key is operated by multiplying a set of coefficients with a set of sinusoid values and continuously scaling the resultant product by an envelope scale factor which changes with time to correspond to the desired envelope waveform.

Abstract: There is provided a first waveform generator which repeatedly generates a first waveform having a relatively short period in response to a first constant parameter, a second waveform generator responsive to a second constant parameter for generating a second waveform having a longer period than the repeatedly generated waveform and gradually approaches to zero in the later half of its period, a multiplier for multiplying the first waveform and the second waveform to form a musical tone waveform element, and means for resetting the waveform generating operations of the first and second waveform generator at a period corresponding to the tone pitch of a depressed key. Sequential alignment of the musical tone waveform elements constitutes a musical tone waveform having a tone frequency determined by the resetting period. The changes in the parameters cause changes in the tone color.

Abstract: An electronic circuit for simulating the sound of a skin head percussive instrument struck with a stick includes a pair of ringing oscillators of different frequencies both triggered by pulses from the rhythm pattern generator of an electronic organ, a circuit for combining the output signals from the two ringing oscillators in preselected amplitude proportions, and a circuit for distorting the combined signal in such a way as to non-linearly amplify the combined signal so as to produce an electrical signal having characteristics such that when acoustically reproduced produces a sound highly simulative of that produced when the membrane of a skin head instrument is struck with a stick.

Abstract: A tone control circuit using only one potentiometer to provide bass or treble control is described. An integrator and a differentiator are connected to the input of the circuit and their outputs to the two ends of the potentiometer. Electrical connection between the potentiometer and the input is also made to provide a flat frequency characteristic component in the output signal.

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: A polyphonic electronic musical instrument in which the complex signal delivered by the instrument is made up of successive samples.Each sample in the complex signal is the sum of the samples of the different harmonics of the various notes played, at the corresponding amplitudes. A device for scanning the keys and pedals comprises two or three counters which operate in association with one another to detect the number (i) of each played note out of the 12 or 13 notes in an octave, and also detect the number of the corresponding octave (n) and successively calculate the various samples of the harmonics of the note (i, n). The set of operations is performed in a sufficiently short time to produce notes of 6- 10 kHz.

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

Abstract: 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: A plurality of tone signals corresponding to one note and having the same fundamental frequency and different harmonic components are modified in amplitude according to the shape of an envelope signal generated upon key depression and having an amplitude proportional to the key depression speed. One of the amplitude-modified tone signals is clipped at a predetermined level and then mixed with another amplitude-modified tone signal. The frequency spectrum of the resultant tone signal varies with time like a piano.

Abstract: An electronic musical instrument of a waveshape memory type comprising: a plurality of waveshape memories for storing waveshapes of different tone color, and means for variably mixing the outputs of the plurality of waveshape memories for generating tone signals of varying tone color. The mixing ratio of the different waveshapes may be varied with the lapse of time or according to the touch of the key operation or to the tone pitch.

Abstract: A LSI (large scale integrated circuit) device is disclosed which generates 12 output frequencies related to each other by a multiple of the twelfth root of two from a common time base without the use of parallel divider or shift register strings. The output frequencies comprise the top octave, or a multiple thereof, of the frequencies of an electronic musical instrument. A binary counter serves as a common time base and encodes each wave form period in a form of a binary code. A binary processing circuit associated with each output frequency stores the count position of the next desired wave form transition and updates the stored code after each transition has occurred. The binary processing circuitry comprises a latch circuit, a binary full adder or ROM (read only memory), a digital comparator or ROM, and a J-K flip-flop circuit. The outputs can be easily modified in both actual frequency and waveform symmetry.

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: 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: Musical tone signals are produced in an electronic musical instrument by calculating the amplitudes at successive sample points of a complex waveshape and by delivering these calculated amplitudes one after another in time sequence. A recursive algorithm is implemented to calculate each amplitude, using one or more sets of parameters and also the calculated amplitudes for a plurality of the preceding sample points. This musical instrument can produce a variety of musical sounds which realistically simulate those of the various existing natural musical instruments including percussion instruments, simply by suitably determining the parameters.

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: In an electronic musical instrument, the amplitudes of respective partial components constituting a composite waveshape at successive sample points are produced, these amplitudes are multiplied, at regular time intervals individually by coefficients each being associated with corresponding partial components to obtain the amplitudes weighted, these weighted amplitudes being accumulated successively to obtain the net amplitudes weighted of the composite waveshape for each sample point. The net amplitudes are converted to a musical sound by sounding means. The coefficients are repetitively calculated at another regular time intervals, each of which being longer than the foregoing regular time interval, by implementing the algorithm of a certain function of time, as the multiplications are carried out.

Abstract: In an audio amplifier for amplifying signals from an electric guitar or the like having a conventional tone control circuit for selectively emphasizing input signals in the bass, middle and treble frequency ranges of the instrument, a multifilter circuit for emphasizing input signals with frequencies in selected, relatively narrow, frequency bands in the upper portion of the frequency spectrum to minimize aural fatigue. The multifilter circuit comprises a plurality of parallel connected, two-pole, resonant filter sections with different, relatively narrow, resonant frequency bands separated from one another by an amount on the order of 1/4 octave and forms a signal path that supplements the signal path provided by the conventional tone control circuit. The signals produced on the output of the tone control circuit are mixed with the multifilter output signals.

Abstract: The present invention is an integrated circuit for an electronic musical instrument comprising: a plurality of frequency divider chains receiving a plurality of input signals for dividing the frequencies of the input signals one after another and corresponding to a plurality of series of adjacent notes which are chromatically arranged in turn in a twelve-tone of a musical scale, respectively; keyer-gates for switching on and off the input signals and output signals of the frequency dividers of the frequency divider chains respectively; and adding means for adding at least two output signals of the keyer-gates which correspond to the adjacent notes chromatically arranged to each other, so as to produce output tone signals therefrom, respectively.

Abstract: An electronic musical instrument providing continuous cybernetic tone finding controlled by functions of the human mouth. The instrument includes a mouthpiece into which air is to be blown from the mouth of a player having a measuring apparatus at least partially mounted therein. The measuring apparatus includes an arrangement for producing a pitch determining signal representing a measure of the mouth cavity of the player and a volume determining signal representing the velocity or pressure of the air blown into the mouthpiece. Tone generating apparatus is provided for generating a tone signal whose frequency varies with the level of a control signal applied thereto with a control signal being applied to the tone generating apparatus in accordance with the pitch determining signal and having a level representing a measure of the mouth cavity of the player.

Abstract: In an electronic musical instrument, such as an electronic organ, the speech characteristics of Vox Humana and similar reed organ pipes are simulated by applying a repeating series of pulse groups separated from each other, which groups each contain a short sequence of two or more pulses, to a sharp cutoff low-pass filter for converting the series of pulse groups into a sound producing signal simulative of the sound signal produced by a Vox Humana or similar organ pipe. The repeating series of pulse groups is obtained by nonlinearly combining square wave tone signals from two or more different octaves of a conventional phase-locked tone generator. The synthesized repeating series of pulse groups, one series for each note of the instrument, are applied to a single low-pass filter, or grouped and applied to a small number of filters.

Abstract: A keyboard operated electronic musical instrument such as an electronic organ is disclosed which generates a musical tone signal by mixing together two different musical tone signals of different waveforms and which changes the sound of the generated musical tone by changing a the amount of mixing of the two signals. A clipping gate with a so-called sustain function is included for controlling the attenuation of an input signal as it passes to an output terminal while clipping the input signal gradually and smoothly so that the musical tone does not disappear instantly but attenuates gradually after the release of a depressed key. The input signal to the clipping gate circuit is a square wave signal, and a square wave signal derived at an output thereof is converted to a waveform other than a square wave.

Abstract: In a musical polyphonic tone synthesizer, musical waveshapes are produced by voltage controlled oscillators. The analog frequency control voltages are created by converting stored digital numbers to analog voltages. The selection of these digital numbers and their assignment to a plurality of voltage controlled oscillators is controlled by detecting switches actuated on a keyboard. Provision is made for operating the oscillators over the full frequency range of an electronic musical instrument's keyboard. Automatic tuning means is incorporated to adjust the conversion reference voltage for each oscillator to keep the musical instrument in tune by locking the set of voltage controlled oscillators to a stable reference oscillator. Tuning the reference oscillator thereby tunes the set of voltage controlled oscillators while retaining equal tempered musical frequencies.

Abstract: A tone source apparatus for an electronic musical instrument is characterized in that at least one cycle of a musical-tone waveform, which it is desired be produced, is depicted as a sequence of section lines and a series of pulses having regular intervals is varied, by a pulse-density varying circuit, in pulse density in accordance with the degrees of inclination of the respective section lines. The resultant series of pulses having varied pulse density is formed, by a waveform forming circuit, into the desired musical tone waveform. The pulse-density varying circuit comprises a first counter to which is applied as an input, the aforementioned series of pulses having regular intervals. A second counter is connected, in series or in parallel, to the first counter and a decoder is connected to an output terminal of the second counter. A memory circuit is connected to the output terminals of the decoder.

Abstract: A tone generator system for an electronic organ which is capable of being fabricated into an LSI structure and receives a saw-tooth wave or staircase wave as an input thereto comprises a frequency divider for the saw-tooth wave or staircase wave including a ladder resistor network and a complementary MOS FET devices, an analog switch having a wide dynamic range and a high linearity in input-output transfer characteristic constructed by MOS FET devices to serve as an indirect keying means, a sustain means including a novel structure of a variable impedance element which is constructed to control a channel current in a MOS FET device by varying the potential distribution in the source region, and an impedance coverter constructed by complementary MOS FET devices and free from a D.C. level shift. With the above arrangement a tone generator system of high quality for an electronic organ is provided.

Abstract: The invention is directed to a waveshape generator capable of producing a desired waveshape by previously storing basic amplitudes obtained by sampling one period of the waveshape at a coarse interval and calculating amplitudes with a fine interval between the basic amplitudes. While basic amplitudes A and B are sequentially produced at a coarse interval in response to an integer portion of the input data, a function X (c) is produced in response to a fraction portion of the input data. Waveshape amplitudes are interpolated between the basic amplitudes by carrying out calculation of A + (B - A) .times. X(c) in response to these values A, B and X(c). A special form of function X(c) is also used for applying interpolation by a partial waveshape of a trigonometric function wave. An example of a musical tone waveshape generator is also described in which different waveshapes are produced depending upon different tone ranges by moving the position of a radix point for each of the different tone ranges.

Abstract: An electrically amplified musical instrument control apparatus for combining control of a broad range of special sound effects in a single housing and enabling a musician to produce single or multiple special sound effects as desired with a guitar while indicating the operational status of each special effect and providing a foot-operated volume control.

Abstract: A waveform converter for an electronic musical instrument wherein an input rectangular wave tone signal is supplied to a frequency-voltage converter to generate a D.C. voltage control signal having a voltage level corresponding to the frequency of the input rectangular wave tone signal; and a one-shot multivibrator is triggered by the input rectangular wave tone signal to produce an output rectangular wave tone signal having the same frequency as the input rectangular wave tone signal. The one-shot multivibrator comprises duty factor control means responsive to the D.C. control voltage signal for determining the duty factor of the output rectangular wave tone signal.

Abstract: An electronic musical instrument capable of producing any desired combination of two tones of mutually different footage. According to the invention, such combination of tones can be produced from only two tone sources without providing tone sources of an equal number to a total number of footage to be coupled. In view of the fact that musical tone waveshape amplitudes of two coupled tones of different footage can be represented by a multiplication term of a sine wave content and a cosine wave content, these two waveshape contents are individually calculated and then combined to form amplitudes of a composite musical tone waveshape.

Abstract: An electronic organ comprises memory means for memorizing in an analog manner the synthesizing ratio of repetitively occuring waves such as square waves for synthesizing qualities of sound in response to the signals from means for selecting qualities of sound (to be referred to as tablets hereinafter); a mixing circuit for adding the synthesizing ratio for each repetitively occuring wave when the means for selecting qualities of sound are selected; frequency dividers for dividing the oscillation frequencies of top octave generators, an indirect keying circuit for interrupting the current corresponding to the ratio of repetitively occuring waves in response to the repetitively occuring signal waveforms from the frequency dividers and intermittingly interrupting said current in response to on-off signals from a keyboard; a synthesizing circuit for combining the outputs from the indirect keying circuit into a group for each octave; a variable filter for changing the frequency characteristics electronically in re