Abstract: The present invention comprises a ringer interface circuit for generating a ringer signal for controlling a telephone ringer. The circuit of the present invention includes a first frequency divider, a second frequency divider, and a third frequency divider. The first frequency divider is adapted to receive a ringer clock signal and generate a first divider frequency output therefrom. The second frequency divider is coupled to receive the first divider frequency output and is adapted to generate a second divider frequency output using the first divider frequency output. The second frequency divider is further adapted to generate a oversampled audio frequency signal. The third frequency divider is coupled to receive the second frequency divider output and is adapted to generate a period signal using the second frequency divider output.

Abstract: An electronic musical instrument reads data of a musical tone from a waveform memory thereof according to pitch information input thereto, to form a tone signal containing a tone amplitude signal indicative of amplitude of the musical tone. The tone signal is passed into a plurality of signal paths to be formed into a plurality of analog tone signals. The plurality of signals paths each amplify the tone amplitude signal according to a note on/off velocity, and attenuate a plurality of modifications of the tone signal, depending on or not depending on the note on/off velocity and the pitch information on the musical tone, to generate a musical tone suitably reflecting the note on/off velocity and the pitch.

Abstract: A device for reading sound waveform data has a waveform ROM for storing waveform data represented as an amplitude in a time series. Sound waveform data is repeatedly read from the waveform ROM. The reading of a single waveform corresponds to a single period. A scale ROM stores a plurality of frequency dividing ratios. A programmable counter divides a signal having a predetermined frequency in correspondence with a frequency dividing ratio output by the scale ROM and outputing a clock pulse. A counter counts the clock pulses and indicates the addresses of the waveform ROM. The scale ROM changes the frequency dividing ratio data during an arbitrary divided period of intervals in the period for reading the waveform data. During the period for reading the waveform by the counters, the sound waveform read out has a single frequency and accordingly a single period. The waveform reading period is divided into m number of intervals.

Abstract: An interruption control apparatus for controlling interruptions of a performance information processor for processing performance information of a piece of music. The interruption control apparatus includes a first time control unit for regulating the length of a time interval between successive interruptions of the performance information processor according to a pre-set tempo in such a manner that the regulated time interval is limited within a predetermined constant range, and for outputting an interruption signal at the regulated time interval.

Abstract: A system and method for detecting, separating and recording the individual voices in a musical composition performed by a plurality of instruments. The electrical waveform signal for the multi-voiced musical composition is fed to a waveform signal converter to convert the waveform signal to a frequency spectrum representation. The frequency spectrum representation is fed to a frequency spectrum comparator where it is compared to predetermined steady-state frequency spectrum representations for a particular musical instrument. Upon detecting the presence of a frequency spectrum representation corresponding to a predetermined steady-state frequency spectrum representation, the detected frequency spectrum representation and measured growth and decay frequency spectrum representations are fed to a waveform envelope comparator and compared to predetermined waveform envelopes, i.e. frequency spectrum representations during the growth, steady-state and decay periods of the waveform signal.

Abstract: The purpose of the invention is to ensure that when digitally coded music is being reproduced as audio signals and lyrics are being displayed on a screen that the progress of the two operations is synchronized.To this end music reproduction data is processed for reproduction in accordance with division values calculated on the basis of tempo data contained in the said music reproduction data while synchronization with the current position in the lyrics, which are displayed on a visual display unit, is advanced in accordance with values derived through multiplication of the aforementioned division values by a constant factor, thereby ensuring the synchronization of the reproduction of the music and the display of the current lyric position on the visual display unit.

Abstract: An electrical musical instrument includes a scale designator for sequentially and automatically designating a scale on the basis of prestored data of a music piece, and a musical tone signal generator for outputting a musical tone signal including a harmonic frequency on the basis of the scale designated by said scale designator or as a fundamental frequency. A voice detector detects an external voice and the detected voice is divided by a modulator into voice signals in a plurality of frequency ranges. The musical tone signal is modulated in units of corresponding frequency ranges on the basis of the voice signals divided into the plurality of frequency ranges.

Abstract: An electronic tone generator includes a signal-generating oscillator, a memory circuit for storing tone and time data for each note to be produced and two note producing circuits, each including a first programmable counter electrically connected to the memory circuit and the signal-generating oscillator and for variably dividing signals outputted by the signal-generating oscillator in order to sequentially produce notes of predetermined frequencies and durations according to the data read from the memory circuit. The note outputs of the two note producing circuits are interrelated to produce a music effect.

Abstract: A sound synthesizing circuit has means for synthesizing sound digital data in a pitch period of a sound to be synthesized and means for producing a sound analog signal according to the synthesized sound digital data. The synthesized sound digital data are sequentially transferred to the producing means according to a sequential sampling pulse. The sequential sampling pulse has a predetermined interval and a corrected interval different from the predetermined interval in one pitch period of a sound to be synthesized. Thus, a sound of good quality with an arbitrary interval can be synthesized in a wide scale by a simple hardware integrated circuit in a small semiconductor chip.

Abstract: An electronic musical instrument is provided with a first programmable counter for generating a reference clock signal corresponding to a musical frequency and a plurality of cascade-connected programmable counters which are each triggered by the preceding programmable counter. A multi-level signal which assumes one of a plurality of levels for each period specified by one of the cascade-connected programmable counters is output as a primary waveform. The electronic musical instrument is capable of setting various variations of the primary waveform abundantly containing harmonics and is satisfactory in the tone quality and in the degree of freedom in setting tones, and hence is of high musicality.

Abstract: An electronic musical instrument are provided a plurality of tone production channels to produce musical tones polyphonically. Each of the tone production channel includes a first counter which divides clock pulses by either one of N and N+1 to deliver an output pulse. A second counter and a control circuit are further provided in the instrument, which are commonly used for respective tone production channels. The second counter counts, on the time division basis, the output pulses from the first counters, and the control circuit designates the dividing number of the first counter is relation with the counted value of the second counter. Each of the tone production channels produces a tone signal having a frequency predetermined by the combination of N and N+1. By time divisionally using the second counter and the control circuit, the construction of the instrument is simplified.

Abstract: An electronic musical instrument comprising a code generator responsive to the operation of each of the keys for generating a first code indicating a tone pitch and a second code indicating an octave associated with the operated key. A first variable frequency divider is presettable to a first count value as a function of the first code for counting master clock pulses supplied from an oscillator and generating a first divider output when the first count value is reached. A second variable frequency divider is presettable to a second count value as a function of the second code for counting the first divider output and generating a plurality of pulse trains having octave frequency relationship. A digital-to-analog converting means is provided for converting the pulse trains into an analog signal.

Abstract: A tone generator as disclosed that produces a specified waveform by reading out values contained in one of a number of arrays stored in an EPROM. Variations of the desired waveform are stored in a number of these arrays. A microprocessor is used to select among the various arrays stored in the EPROM to compensate for distortion in subsequent processing of the waveform, as a function of amplitude and frequency. The rate at which the values are read from the selected array determines the frequency of the tone produced. Also disclosed are various means for processing the waveform suitable for use in audiometric testing.

Abstract: Disclosed is a frequency-selectable signal generator in which a numeric datum is parallel-transferred to a full adder circuit repeatedly under the control of clock pulse signals, thereby outputting an overflow signal, which is a precise division of accumulation of repeatedly inputting numbers. The frequency of the overflow signal varies with the number represented by the numeric datum. The output signal has a regular pulse-to-pulse interval, and therefore it can be used in producing a musical note.

Abstract: A just intonation electronic keyboard instrument comprises a plurality of tonality selection switches for selecting each key from among twenty-four just intonation keys, a control circuit for determining one or a plurality of just intonation keys according to the manipulation of said switches, a variable frequency oscillator having its output oscillation frequency varied in accordance with the selected key, and a frequency dividing circuit having frequency dividers which are varied of their frequency dividing ratios according to the selected key. The number of tonality selection switches is less than twenty-four. The control circuit discriminates the selection to a major scale or a minor scale, and discriminates one or a plurality of keys from each of twelve keys from C through B, and determines one or a plurality of selected just intonation keys, according to the manipulation of said intonation selection switches.

Abstract: A frequency divider which divides clock pulses to obtain the clock frequency of a desired dividing ratio comprises a binary counter, cycle data forming circuit and inhibit circuit to which the dividing ratio is fed in the form of the dividing ratio data.The counter counts the clock pulses, and the cycle data forming circuit converts the count value of the binary counter to a cycle data in which a certain single bit only becomes a logical state "1" and the rest of the bits are a state "0". The bit which becomes "1" in the cycle data is uniquely determined by the count value. Further, each bit of the cycle data becomes "1" in proportion to the weight of the each bit. With the cycle data being thus formed, the dividing ratio data is simplified.The inhibit circuit receives the cycle data and the dividing ratio data to suspend the counting operation of the binary count if the bit of the dividing ratio data corresponding to the bit of the cycle data whose state is "1" is also "1".

Abstract: Equal-ratio scales offer a choice of semitone accuracies ranging from a thousandth cent to a millionth of a cent, any note of which may be selected as a reference for a fully chromatic just-intonation scale whose ratios are absolute and may be modulated in all 15 tonalities, i.e., to signature keys in seven sharps and seven flats.

Abstract: A synchronizing signal generator includes a tape recorder which is adapted to record click signals in response to actuations of a manual switch. Counting clock signals go on while the click recorded signals are reproduced, especially during a length of time extending from receipt of a particular one of the click signals to receipt of the next succeeding click signal. The resultant count is divided by a given numeral value and then the quotient is stored. The clock signals developing between the respective click signals are further counted during the course of reproduction of the click signals from the tape recorder and a pulse signal is delivered whenever the instantaneous count coincides with the stored quotient. Tempo clock signals are obtained through the division of the pulse signal at a selected division ratio out of a plurality of division ratios. The tempo clock signals are fed to a sequencer which in turn generates a control voltage and gate signals synchronous with the tempo clock signals.

Abstract: An electronic musical instrument has a generator assigner for supplying note data and octave data by key stroke entry, a top octave synthesizer for generating 12 of the highest pitch signals for each note, a circuit for selecting one highest pitch signal from the 12 highest pitch signals according to note data, a binary counter for dividing one highest pitch signal to produce several pitch signals, and circuits for selecting one pitch signal out of several pitch signals obtained by the binary counter. The circuits are further controlled by both octave data and note data to generate octave series tone signals and non-octave series tone signals such as quint series tone signals.

Abstract: A tone generator for electronic musical instruments, useful in particular for the modular composition of an electronic organ, comprising a plurality of inputs corresponding to a keyboard octave of the musical instrument. The inputs are connected to a plurality of groups of analog modulators which receive, respectively, tone signals produced by a tone generator and submultiples thereof produced by a plurality of toggles according to the number of footages desired on the output of the groups of modulators. The tone generator includes an audio frequency modulator having a high modulation index with full modulation depth remaining substantially constant over the whole supply voltage range.

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

Abstract: A musical note oscillator producing notes at musical intervals having high resolution and high frequency stability achieved with an economy of components and control signals. The oscillator may be operated to provide multiple notes simultaneously and independently; and it is described in the context of a musical instrument.

Abstract: A digital oscillator generates a basic pulse having a period which is a predetermined large number of times of a clock pulse period. During the basic pulse period are allotted a predetermined small number of time slots defining submultiple frequency channels. There is provided a shift register having the channel number of stages, each stage being assigned to each channel. The contents of the respective stages are changed at respectively different periods which are multiples of the basic pulse period. The contents are taken out timewise-serially, one at a time, stage by stage, and superimposed on the basic pulse to constitute a time-division-multiplexed wave data signal. The delivered signal is demultiplexed to form individual waves having respectively different frequencies which are submultiple-related to the frequency of the basic pulse. This generator is very suitable for electronic musical instruments, as a single line transmits plural wave data.

Abstract: A circuit for obtaining a musical-scale frequency in an electronic musical instrument comprises a multi-stage binary counter for counting reference clock signals to obtain a respective musical-scale frequency based on the tempered scale, circuit means for taking a plurality of specific different count values from the binary counter, and selection circuit means for selecting the output of the circuit means according to each musical-scale.

Abstract: An electronic tone generator capable of providing improved musical and tone quality by providing a primary melody and a secondary melody such as an accompaniment or the like is provided. The electronic tone generator of the instant invention is characterized by the use of a primary electronic scale generator circuit for producing a primary scale signal representative of a primary melody scale and a secondary electronic scale generator circuit for producing a secondary scale signal that is representative of a secondary melody and that is distinct from the primary scale signal. The primary scale signal and second scale signal are respectively shaped and summed and thereafter applied to an electro-acoustic transducer in order to produce music having a primary melody and secondary melody of considerable musical quality.

Abstract: Each harmonic of the ten provided is represented by a pair of binary-valued signals; one having the form A .sym. B .sym. C, where A, B and C are octavely related square waves, and the other being a square wave like C. Each pair of signals is coupled to a resistive divider by coupling elements in an additive relation under control of an individual adjustable voltage source. The coupling elements are weighted so as to minimize distortion in the signal resulting from the mixture. The resistive divider preemphasizes the signals representing each harmonic to compensate for a voltage controlled filter in the audio output used to eliminate high order distortion components. In one embodiment a .div.3 counter followed by a binary counter provides the binary-valued signals for harmonics of order 0.5.times.2.sup.n, where n is an integer, and a binary counter driven in parallel with the .div.3 counter provides the binary-valued signals for harmonics of order 1.5.times.2.sup.n.

Abstract: A divider keyer circuit arrangement for a synthesis organ utilizing four integrated circuit chips to generate the notes for a 61 key manual with 9 harmonic drawbacks or tabs. On-chip cross wiring and the use of clock lines for synchronization pulses and other design techniques enable the use of four identical integrated circuit chips in standard 40 pin packages to be used to generate the full complement of notes for a 61 note keyboard.

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

Abstract: An electronic tone or note generator capable of providing improved musical and tone quality and special sound effects by mixing the outputs of a plurality of note-signal-producing circuits is provided. The electronic tone or note generator of the invention is characterized by the use of a primary electronic note circuit for producing a primary note signal which is a portion of a primary melody, and a secondary electronic note circuit for producing a secondary note signal that is musically related to the primary melody. The relationship between signals can be a time lag between the outputs of the two note signal circuits or a small difference in frequency between the signal outputs of the two note circuits. Additionally, each note signal circuit can output alternate notes of a continuing melody such that a note from one circuit may persist while the next note from the second circuit is played.

Abstract: Instant scale shifting by predetermined increments is provided in a musical instrument tuning device by means of a programmable phase locked loop and crystal-controlled oscillator combination. The incremental scale steps are extremely accurate without need for recalibration and with no change in the tone intervals.

Abstract: An automatic rhythm generator for use in an electronic organ is made more efficient, from the standpoint of rhythm pattern storage, by use of a zero suppression technique. Null instructions, the sole function of which is to allow a clock interval to pass without sounding an audible beat, are eliminated entirely from storage, and thus do not consume any memory capacity. In order to skip the necessary silent clock intervals before the next audible beat, each beat instruction which is stored at a memory address may include an encoded skip instruction commanding a number of clock intervals to be skipped before passing on to the next beat instruction at the next memory address. Alternatively, the skip instruction, in a stored program instrument, may come from software. In either case, the skip instruction controls a programmable frequency divider, which causes clock interval skipping by dividing down the clock frequency to a lower rate before it reaches the memory address counter.

Abstract: A high resolution fractional divider is responsive to a multi-bit divisor representative control word and a clock signal for developing an output signal having an average frequency of the form n-f, wherein n is an integer determined according to the most significant bits of the control word and f is a fraction determined according to the least significant bits of the control word.

Abstract: The disclosure describes 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 repetition rates of which are detuned with respect to each other so that the sound of a 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: An integrated keyer system for use in electronic organs comprising a plurality of discrete integrated circuit chips each corresponding to two adjacent octaves of the keyboard and connected in series to accommodate the entire keyboard. The keyer system is adapted for use in multiplexed systems wherein the keyswitch closure information is encoded in a time division multiplexed data stream fed through a plurality of the keyer chips, which are connected in series. Each of the keyer chips includes a plurality of tone inputs and outputs and a divide-by-four circuit for lowering the tones in by two octaves. The keyer chips also include serial data inputs and outputs and a demultiplexer for demultiplexing the serial data stream at the serial data input to produce a plurality of control signals corresponding to keydown signals in the serial data stream, which are fed to the individual keyers.

Abstract: An electronic organ uses several top octave synthesizer circuits for producing the various tones used in the organ. Each of the top octave synthesizers is capable of producing any tone which can be produced by the organ. As a consequence, the outputs of each synthesizer are applied to a coupler circuit, which in turn is connected to an octave assignment switching tree for directing the tones coupled to the inputs of the switching tree to individual leads, each corresponding to a different octave in the range of tones produced by the organ. The similar octave leads from each of the different octave switching circuits are connected together to common flute octave buses, so that the filters connected to the output buses have substantially fewer tones appearing at the input than one which would have the full tone range of the organ. Typically, the range of tones appearing at a filter input is one octave or less.

Abstract: In an electronic organ of the time-sharing type, a single clock source drives a number of variable divisor frequency dividers which are assigned different divisor values to produce different musical tones at different times. In order to prevent phase synchronism between two simultaneously operating dividers, and thus achieve a rolling phase relationship which is perceived as a chorus effect, divisor values are employed for the two frequency dividers which are not in a whole number relationship. If the two dividers are generating octavely related notes, the divisors used have a ratio not quite equal to the nominal 2:1 value which musical theory requires. Moreover, the exact value of the ratio varies from note to note within each octave so that the rate of phase roll is not monotonously the same for all notes. Alternatively, if the two dividers are both generating the same note, then the divisors used have a ratio which is not quite equal to the 1:1 value which musical theory requires.

Abstract: An electronic musical instrument develops digital pulses corresponding to electronic waves that are subsequently converted to audio sound such as by means of a loudspeaker. The musical instrument is provided a source of master frequency generated binary related numbers which act in conjunction with a read only memory, an adder, and a comparator, and also a counter, to control a J/K flip-flop to produce a pulse train output in which for any given cycle the starting time and duration of each pulse is controlled, thereby to determine the harmonic content of the electronic waves that are converted to audio sound.

Abstract: The device of the invention extracts a fundamental frequency from signals coming from a played musical instrument. From this is synthesized a waveform with the same fundamental frequency which can be given an arbitrary form, so that an audical impression of e.g. a violin, a trumpet or a guitar can be given to sound produced by the waveform. The waveform is produced by making a pulse train with frequency n times the fumdamental frequency, leading the pulse train to a counter activating cyclically and sequentially n different outputs. The outputs are summed with different and adjustable weights, and the waveform is determined by adjusting the n weights. The number n can be any number. An embodiment is shown with n=16.

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

Abstract: An electronic musical instrument has a keyboard including a plurality of scale keys and a plurality of chord keys. Musical sounds are generated by a programmable frequency divider network capable of producing different output frequencies, depending on which keys of the keyboard are activated. A decoding means connects the keyboard and the programmable frequency divider network to supply signals which cause the programmable frequency divider network to produce different output frequencies, depending on which keys of the keyboard are activated. Means connect the scale keys and the chord keys for altering signals supplied from the chord keys to the programmable frequency divider network, depending on which scale keys are activated. On this basis, compatible chords may be generated with the chord keys for a melody being played with the scale keys. The frequency divider network utilizes lowest common multiples and prime numbers, which substantially eliminates the potential for producing dissonant sounds.

Abstract: A frequency divider for a tone source for an Arabian scale in an electronic organ of the type wherein musical tone signals for a standard musical scale, musical tone signals higher than the same by 50 cents and musical tone signals lower than the same by 50 cents can be obtained from the output signal of a main oscillator. The output signal of the main oscillator is frequency-divided by at least one frequency divider to obtain an output signal. The aforesaid frequency divider comprises a counter and an AND circuit. An input terminal of the frequency divider is connected through the counter to an input terminal on one side of the AND circuit and is connected directly to an input terminal on the other side of the AND circuit.

Abstract: A method and apparatus for generating tones for an electronic organ in which a number of oscillators less than the tones in a scale are provided with the outputs thereof divided by selected divisors to produce a range of frequencies related to one another as the tones of the chromatic scale. The range of frequencies thus developed can be employed as, for example, the top octave for one or more of the organ keyboards and divided down to produce pitches corresponding to other octaves of the keyboards.

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: DC programmable counters with DC switching provide instant retuning of an entire keyboard of a programmable electronic musical instrument to any one of a plurality of different scales.

Abstract: The embodiment of the invention disclosed herein is directed to an electronic musical instrument of the keyboard type wherein the audio frequency signal information is derived from a multi-frequency generator formed by an electronic oscillator and a plurality of divider circuits, and wherein programmable divider circuits are associated with the various keys of the keyboard to generate associated tone signal information. The programmable divider circuits are formed on a large scale integrated circuit chip and enable alteration of the numerical divisor so that different tone signals can be obtained from the same electronic circuitry thereby enabling the same type of LSI chip to be used for many different circuit configurations. The LSI chip also provides a scanning circuit that scans an X-Y matrix switching arrangement to determine which one of a plurality of key switches is closed.

Abstract: A pulse generator especially for an electronic musical instrument in which a "D" type flip-flop is employed with the logic level at the data input thereof being transferred to the output in conformity with the supply to the clock input of a fixed frequency rectangular wave and the supply to the clear input of a rectangular wave having a frequency which is a whole multiple of the fixed frequency. The output at the output terminal of the flip-flop is a pulse having a duty cycle of predetermined length. The pulses at the output terminal are, of course, repetitive and remain at the same duty cycle without variation. By using a plurality of the flip-flops, each having respective inputs to the clock and clear terminals, a desired range of pitches can be generated.

Abstract: An electronic musical instrument in which a plurality of order pulse generators and a plurality of musical-tone-waveform forming circuits are connected in order to a tone-source-signal pulse generator. Interposed in each of a plurality of circuits diverging from the output terminal of the tone-source-signal pulse generator to the order pulse generators is a pulse-counter circuit which has a variable frequency-dividing ratio. On the output side of the pulse-counter circuit, a frequency-dividing ratio-setting signal-generating counter circuit is provided which generates a signal for setting the frequency-dividing ratio thereof.

Abstract: An electronic musical instrument in which a plurality of order pulse generators and musical-tone waveform forming circuits are connected in order to a tone-source-signal pulse generator. A first pulse-counter circuit and a second pulse-counter circuit are provided in each of the circuits diverging from the output terminal of the tone-source-signal pulse generator to the respective order pulse generators, so that the output signal of the tone-source-signal pulse generator is frequency-divided by the first pulse-counter circuit into 1/x and is then applied as an input signal to the order pulse generator, while the output signal of the tone-source-signal generator is frequency-divided by the second pulse-counter circuit into 1/n and is then applied as a reset pulse to both the first pulse-counter circuit and the order pulse generator. The numbers x and n are integral numbers with the relation 0<x<n. Each musical-tone waveform forming circuit has a sampling number of from 10 to 40.

Abstract: An electronic musical instrument including two or more keyboards individually capable of selecting, simultaneously, any twelve out of at least 1,024 discrete pitches per octave to produce scales of twenty-four or more notes per octave using conventional keyboards. It can also produce two or more completely independent tones with a specific pitch or phase difference between them for research in music theory, music history, ethnomusicology, acoustics, and monaural and binaural beats.

Abstract: Generator for producing the tones of a musical scale in electronic musical instruments, one master oscillator driving a chain of frequency dividers in a manner such that at the output of each divider a tone is produced which is lower by a semi-tone than the tone at the input of the divider, the final divider of the chain being connected to the input of the first divider via a frequency multiplier which multiplies by a factor of 2, while the master oscillator can be connected to any one of the dividers, in which case the connection of this divider to the preceding one is broken in order to permit transposition without the use of additional dividers.