Abstract: An electronic musical instrument is of a type in which a particular note tone and tones corresponding to the remaining notes among depressed keys are alternately and repeatedly produced in accordance with tone production timing signals having a predetermined period. The tone production timing signals are produced by frequency dividing tempo pulses generated from a tempo pulse oscillator. An alternate production control is conducted by gating alternately signal of the particular note tone and signals of other tones and delivering to a sound system. The period of the tone production timing signals can be controlled by a circuit which detects depression of plural keys.

Abstract: An electronic musical instrument employing top octave synthesizer circuits (TOS circuits) for generating the musical tones to be reproduced by the instrument employs a single master oscillator common to all of the top octave synthesizer circuits for supplying the trains of clock pulses to the synthesizer circuits for their operation. To prevent phase-locked conditions from existing in the frequencies produced by different synthesizers, the clock pulses from the master oscillator are supplied to the synthesizers through coincidence gate logic circuitry which is controlled by means of a low frequency oscillator and a divider or shift register circuit to delete different ones of the clock pulses from the clock pulse signal trains for each of the different synthesizers. This causes all of the frequencies obtained from the synthesizers to be slightly different from one another, independent, and not phase-locked.

Abstract: A digital technique for triangular musical waveform generation is disclosed. A musical scale value corresponding to a selected note is repetitively added to produce an ascending series of non-consecutive numbers which is stored in a latch. A carry output from the limited modulus latch is used to switch a flip-flop which then enables an inverter to reverse the slope of the number series. Alternating reversals produce a rising and falling numerical staircase of controllable slope. This can be directly converted into a smooth triangular waveform, or alternatively it can be used as a series of memory addresses for table look-up purposes. The triangular waveform may be symmetrical, or it may have a controlled degree of asymmetry. Duplicate triangular waveforms with a small frequency mismatch may be used to produce a chorus effect. Or plural triangular waveforms with octavely related frequencies may be used as footages related to a single note, again with a slight frequency mismatch for chorus purposes.

Abstract: An electronic musical instrument incorporates one or more pressure sensitive push-button controllers actuable independent of the keys or other note selecting elements of the instrument to vary a corresponding number of musical parameters. The specific controllers provide a sensitive, smooth, repeatable parameter variation in response to both the location and the force of the player's touch.

Abstract: An electronic musical instrument of a partials synthesis type and the partials are processed in a time division multiplex fashion. One cycle of the time division multiplex sequence consists of a plurality of processing time slots, which are divided into two to four groups. Each group of time slots are used for processing partials which form a discrete musical tone. Thus two to four types of musical tones can be formed at the same time, which realizes an ensemble performance.

Abstract: In an electronic organ or the like constructed of a plurality of large scale integrated circuit (LSI) chips, the present disclosure relates to a generator chip. The chip is operative over one octave of notes, and a string of chips is cascaded to provide as many octaves as there are in the instrument.

Abstract: A musical tone forming device comprises circuit system of digital calculation realizing frequency modulation technology in three different modes. In the first mode a plurality of frequency modulated waveforms are individually calculated in response to key depression and resultant data is added together to provide a musical tone signal, in the second mode, a signal waveform having a frequency corresponding to a depressed key is frequency-modulated with a plurality of signal waveforms, and in the third mode a signal waveform of a frequency corresponding to a depressed key is frequency-modulated in a multiple manner with a plurality of signal waveforms. Throughout these systems, the same component parts are commonly used and tone signals of the respective systems can be produced by a simple switching operation.

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

Abstract: There is disclosed herein a music synthesizer which responds to a music note played by a music instrument. The synthesizer has an envelope generator which generates a control signal in relation to the input signal to control the loudness of the synthesized note. Also, the synthesizer has a pair of voltage controlled oscillators, one of which provides a signal having a frequency related to the frequency of the input note, and the other of which provides a signal having a frequency related to the frequency of the input signal offset by the ratio of the difference between a programmed note and a referenced note, such as A440. The programmed note is that note following the operation of a control switch. The synthesizer further includes a series of footpads which control various functions of the synthesizer, such as programming the programmed note, to allow the user to control the synthesized sound while playing an instrument.

Abstract: A device is described for musical instruments, and particularly stringed musical instruments such as a guitar, which can controllably and selectively sustain the musical sounds produced by the instrument. The device includes an electrical pick-up proximate to the strings of the guitar for generating electrical signals which correspond to the vibrations of the strings. The signals are amplified by the device and are converted in a loud speaker or other transducer mounted on the instrument and proximate to the strings into mechanical vibrations which sympathetically reinforce the initial vibrations and maintain the strings in a vibratory state and thereby sustain the sound.

Abstract: A manually operated pressure sensitive button assembly is arranged by the side of the keyboard on the top front panel of the instrument, each button being electrically and operationally coupled to an associated element in the main processing system of musical tone signals, in order to control musical tone components such as tone pitch, tone color, tone volume and modulation effect quite concurrently with minimal interruption of the manual operation on the keyboard.

Abstract: When the frequency of an input sound signal applied to a shifting type echo-machine is close to that of the shift pulse thereof, a false signal appears at the output terminal of the echo-machine, in addition to the other type of noise signal caused by inclusion of the shift pulse component in the output of the same. The present invention is an echo-machine provided with first and second low pass filters, arranged before and after the delay element included in the echo-machine respectively, with a variable cut-off frequency which varies in accordance with the frequency of the shift pulse thereby eliminating such an erroneous signal and the shift pulse component from the output signal of the echo-machine.

Abstract: For generating tones in an electronic musical instrument, there are provided multiple master frequency sources, a different source for each octave, differing in frequency from each other by a factor which differs from two by at least one semitone, each of which is coupled to a respective frequency synthesizer all of which have the same dividing ratios, to divide down the frequency of its master frequency source to pitches of the twelve notes in the intended octave. In one embodiment the sources are separate master clock pulse sources, and in another embodiment a pulse train derived from a single clock pulse source is applied to the frequency synthesizer for the highest octave, and the pulse train applied to each of the other synthesizers is derived from the pulse train supplied to the frequency synthesizer for the next highest octave by dividing the pulse repetition frequency thereof by a factor which differs from two by one or more semitones.

Abstract: A musical instrument tone generator comprises a clock circuit including means for developing an interval code representing the number of musical intervals to be swept by a tone signal. An output clock signal is produced in response to the interval code for causing the swept tone signal to exhibit a rate of change varying exponentially with time such that a number of musical intervals are swept in a corresponding number of equal time intervals. Means are provided for suitably updating the output clock signal in response to the modification of an on-going frequency sweep in order to maintain the foregoing correspondence between the number of musical intervals swept and the time duration of the sweep. In another embodiment, the output clock signal is effective for operating the tone generator for developing a tone signal sweeping one or more musical intervals in an equal time interval.

Abstract: In an electronic musical instrument of digital processing type, key codes are stored in a memory channel by channel for respective tone productions. The stored key codes are utilized for determining pitches of respective tones to be produced. Upon depression of new keys, the formerly stored key codes are automatically added or subtracted channel by channel with the value for a certain note step toward the new key codes at a certain clock rate defining a glissando speed. Thus automatic glissando performances are easily realized.

Abstract: An electronic music synthesizer capable of simulating a wide variety of musical effects, wherein the settings which create the various effects are hard wired on a plurality of selectable circuit boards so that programming of the instrument can be accomplished by the player with minimum effort. The synthesizer encodes a plurality of keys on the keyboard and selects a tone from the tone generator corresponding to the depressed key. This tone is fed through a chain of dividers to create the needed footages, which are then fed to voicing cards that create the different tone sources for the synthesizer. These tone sources are fed into a state variable active filter which modifies the timbre of the tone sources in order to achieve the desired frequency-related effects.

Abstract: An apertured insulating strip permits closing a circuit only at contact points defined by the apertures between a low resistance conductor and a high resistance conductor in an electronic circuit of the type which produces musical notes each having a frequency dependent upon the resistance downstream of a particular contact point.

Abstract: A means for controlling special musical effects in synchronism with picking a string of a stringed musical instrument by a pick. More specifically, the disclosure describes a means whereby a signal generated as a result of a pick breaking contact with a string of the stringed instrument initiates a special musical effect. The special musical effect may alter the output of a pick-up generated by vibration of the strings, or may be independent of string vibration and merely initiated by the pick breaking contact with the string. Also, disclosed is a pick having a conductive portion and a nonconductive portion so that picking a string by the conductive portion initiates a special musical effect and picking the string by the nonconductive portion results in the instrument operating in a conventional manner without the special musical effect.

Abstract: An electronic musical instrument is of a time-shared digital processing type and capable of producing musical tones for a special performance. There are provided, at suitable time intervals, time periods in which no key code of a depressed key is produced by a key coder. During these time periods, a signal designating a special performance is generated. In a channel assignment circuit which assigns key codes of depressed keys to plural tone production channels there is provided a channel for an exclusive use for the special performance. A circuit for assigning data for the special performance transmits the data to the channel assignment circuit in response to the special performance designation signal from the key coder so that the data selected from among the key data already assigned to the tone production channels for ordinary performance are sequentially assigned to the channel allotted exclusively for the special performance.

Abstract: An electronic musical instrument comprises a keyboard circuit providing a pitch determining voltage signal whose magnitude corresponds to the note of a key depressed, a rectangular wave generation circuit generating a rectangular wave voltage signal, and a voltage controlled oscillator connected to receive the pitch determining voltage signal and the rectangular wave voltage signal to produce alternately first and second tone signals for trill performance. The tone pitch of the first tone signal depends on the magnitude of pitch determining voltage signal and the tone pitch of the second tone signal depends on the magnitudes of pitch determining voltage signal and rectangular wave voltage signal. The musical intervals between tone pitches of the first and second tone signals depends on the magnitude of rectangular wave voltage signal.

Abstract: In an electronic musical instrument of a keyboard type wherein waveshapes with different tone colors read out from waveshape memories are mixed together at a mixing ratio according to a control signal and the resultant signal is converted to a corresponding musical tone, the control signal is varied with lapse of time and also is controllable in response to the initial speed at which a key of the keyboard is depressed and to the strength of pressure of the key being depressed, in addition to time lapse. Thus, the pattern of tone variation can be variously controlled.

Abstract: Methods and apparatus are disclosed which are utilized in providing a musical instrument useful for composing, teaching, learning and performing music. The instrument includes a pitch detector which responds to an applied input signal to produce and octave code representing the octave in which the input signal is located and a note code representing the note which is closest in pitch to the input signal. The octave and note codes are applied to display means which indicate the octave and note nearest in pitch to the input signal. The octave and note codes are also applied to an automatic pitch generator wherein they control the dividing down of a high frequency clock signal to produce a true pitch signal having the pitch corresponding to the octave and note codes. The automatic pitch generator also has provision for selectively combining octave and note transpose codes with the octave and note codes to achieve any desired degree of transposition of the true pitch signal.

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: 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: 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: A sound system, particularlyuseful for isolating the signals from each of a plurality of different sources disposed closely together, such, as for example, from the components of a drummer's set-up of drums and cymbals. The system includes individual transducers associated with each of the drummer's units to provide separate and mutually independent signal sources. The signals from each source are transduced along an associated channel to provide a discrete path for each. Each of the channels includes a selectively settable tone control means for modifying the signals thereof. Finally, each channel includes means for selectively coupling the output of the associated tone control means to one or more of a plurality of devices applying "special effects" to the input signals thereto.

Abstract: In a keyboard electronic musical instrument of waveshape memory type wherein different waveshapes read out from memories are mixed together at a variable mixing ratio according to variable parameters and then converted to a musical tone, the variable parameters are calculated on the basis of information associated with both lapse of time and the pitch of a musical tone to be produced. Thus, with this musical instrument, it is possible to produce a musical tone varying in the content of higher harmonics with respect to the pitch of the tone assigned to a depressed key and in tone color according to lapse of time.

Abstract: In an electronic organ or the like constructed of a plurality of large scale integrated circuit (LSI) chips, the present disclosure relates to a master control LSI chip having a counter providing multiplexing drive outputs and also having a read only memory (ROM) programmed to provide rhythm voice patterns.

Abstract: An electronic musical instrument having a channel processor. The channel processor includes a tone production assignment circuit and an automatic arpeggio circuit. The tone production assignment circuit includes a key code memory circuit of a plurality of channels and an assignment control unit. A specific channel among the channels is used exclusively for the automatic arpeggio performance while the other channels are used for ordinary respective tone production corresponding to depressed keys by an ordinary key assignment operation responsive to depression of the keys. The automatic arpeggio circuit produces key codes one after another for the automatic arpeggio channel in accordance with the key codes already assigned to the respective ordinary channels and with arpeggio constituent orders in a sounding pattern. The arpeggio sounding pattern which is selected in response to a rhythm to be played contains binary data representing the arpeggio constituent orders.

Abstract: Disclosed is a musical instrument and method for generating musical sound. Digital circuits produce a sequence of numbers which are converted to analog electrical signals which are periodically sampled to drive a conventional speaker. The digital circuits operate in accordance with a method of forming each sample by evaluation of a closed-form expression including a first function of time, either periodic or non-periodic, transformed by a second function of time where the second function is non-linear, non-sinusoidal and differs from the first function. The frequency spectra of the resulting musical sound can be finite and the amplitudes of frequency components do not have unwanted limitations.

Abstract: An arrangement for presetting musical tone effects in an electronic musical instrument in which a first system is provided with a plurality of tablet-shaped switches which are connected through respective memory elements in a memory circuit to respective control electrodes of a plurality of gates for selection of musical tone effects. A second system is also provided with tablet-shaped switches which are connected to control electrodes of gates for selection of musical tone effects. Either one of the first or second system is selected, and the memory circuit has a write switch arranged so that after completion of the writing of output signals of respective tablet switches by operation of the write switch, the memories remain unchanged by the writing, even by operation of respective tablet-shaped switches. The memory elements in the memory circuit of the first system are in a plurality of lines in conjunction with a plurality of line selection switches for selecting the respective lines of the memory elements.

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: A musical keyboard instrument is disclosed for recording and storing a musical performance and then automatically playing back the performance. As is conventional, a keyboard having a plurality of keys is provided, along with musical tone generators that are associated with the keys. In accordance with the disclosed invention, means are provided for sensing, at a sensing time, those of the keys which are activated. A sequence of frames are generated, each frame including digital information representative of the keys that are activated at a given sensing time. The duration of each frame is a function of the relative locations of the keys activated at a given sensing time, and is therefore a duration which can vary from frame to frame. Each sensing time is determined by the previously completed frame, i.e., when a frame is complete, the statuses of the keys are again sensed so that the next frame can be generated. The sequences of frames are stored on magnetic tape.

Abstract: A special effects circuit for use in an electronic musical instrument, preferably an electronic organ, including a filter circuit having variable bandpass characteristics and a tone source supplying a signal to the input of the filter circuit. The bandpass characteristics of the filter circuit are modified in accordance with a control signal. Upon the occurrence of an input signal, a control circuit provides the filter circuit with the control signal at a random or pseudo-random value. The instrument player may select the source of input signals from a variety of sources within the organ thereby determining the times or frequency at which the control signal changes but the value of the control signal is random or pseudo-random. The tone signal output from the filter circuit has randomly or pseudo-randomly attenuated frequency characteristics and is coupled to standard organ output circuits for audio presentation.

Abstract: The electronic musical instrument is provided with a plurality of musical tone generating channels of a number smaller than that of the keys and a channel processor for randomly assigning key information representing depressed keys to the musical tone generating channels. Furthermore the musical elements including the pitch, the tone color and the envelope of the musical tones generated by respective channels are made to be different thereby imparting a random property (casualness) to the generated musical tone.

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: Pedal control circuits for use with an electronic musical instrument, such as a piano, which provide control functions analogous to the actions of a sustaining pedal, of a sostenuto pedal, and of a volume pedal of a conventional piano. Damper circuits operable in conjunction with a sustaining pedal provide an effect analogous to the action of the sustaining pedal in a conventional piano, a latching circuit actuated by depression of a sostenuto pedal operates in conjunction with the damper circuits in a manner analogous to the action of a sostenuto pedal in a conventional piano, and a volume pedal and associated circuitry is operative to determine the level of the output tones only at the moment of strike of the keys, an action analogous to that of the volume pedal in a conventional piano.

Abstract: A device for producing an ensemble effect in an electronic musical instrument. The device has a plurality of parallel electronic delay circuits adapted to be supplied with a musical tone signal, delay time modulating circuits coupled to each of said delay circuits for modulating the delay time in each delay circuit, a modulating signal generating circuit arrangement coupled to the delay time modulating circuits for supplying modulating signals to the respective delay time modulating circuits which are different from each other and the frequencies of which are in an integral multiple relationship to each other. Amplifiers are coupled to each of the delay circuits for amplifying the output thereof, and the amplifier outputs are mixed either electronically or acoustically.

Abstract: Random rhythm-pattern generators have been proposed that can select one of several rhythm-patterns (i.e. pulse trains with different repetition cycles) prepared beforehand, change their playing order, and if necessary change the kind of instrumental musical sounds whenever the beating reaches a predetermined number, in order to produce a random accompaniment rhythm sound. The prior art rhythm-pattern generators played the rhythm-patterns only in a fixed order. Therefore, they had the disadvantage of providing a musical performance which was monotonous. According to this invention, this monotony of performance can be avoided because of the following construction: a random pulse generator supplies output pulses representing plural bits of a binary number to a decoder that in turn supplies an output pulse randomly to designate one of the pulse trains with different repetition cycles.

Abstract: A portamento system is disclosed for use with an electronic musical instrument, and particularly with a monotonic keyboard instrument which utilizes master oscillator/divider elements for tone generation. The portamento system utilizes a voltage controlled oscillator, and an oscillator control circuit comprising a unique combination of a phase/frequency detector and a circuit for varying and controlling lock up rate and expanding the frequency range of the system which may be either a ramp and hold circuit or a frequency tachometer circuit. The voltage controlled oscillator is thus locked on to the input frequency from the electronic musical instrument with substantially zero phase and frequency error. The system is capable of reaching the input frequency as slowly or as rapidly as desired and will operate over a wide frequency range.

Abstract: An electronic musical instrument is provided with a keyboard circuit, a voltage-controlled tone signal generating circuit arrangement and a sequencer for sequentially coupling memorized pitch voltage signals to the voltage-controlled tone signal generating circuit arrangement, thereby realizing automatic arpeggio performance. The sequencer is so connected as to receive a pitch determining voltage signal from the keyboard circuit at a given timing and is so arranged that the magnitudes of pitch voltage signals coupled to the tone signal generating circuit arrangement are shifted in accordance with the pitch determining voltage signal from the keyboard circuit, thus achieving transposition of arpeggio.

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

Abstract: An AC keying transient is simulated in a DC keyed electronic musical instrument by gating a pseudorandom frequency noise source output to the audio output circuit of the instrument during a brief time interval initiated by a legato pulse. The level of the noise is randomly selected from a range of values of a triangular wave form. The amplitude range of the triangular wave form is determined for each keyboard manual by chopping the highest drawbar voltage setting with an approximately 20 percent to 80 percent duty cycle higher frequency rectangular wave pulse gated by a low frequency square wave. The variable duty cycle wave form serves as an amplitude control for all keyboards with an equal effect being provided by the individual drawbar voltage settings for each keyboard. The chopper output is filtered to remove the variable duty cycle pulses leaving the triangular wave form which is integrated from the 6.8 hz square wave signal.

Abstract: An ensemble effect is produced in a digital tone generator by providing a master data set of words having values corresponding to the relative amplitudes of equally spaced points along one cycle of the waveform of the audio tone. These values are transferred sequentially during repetitive cycles at a rate proportional to the pitch of the desired musical tone to a digital-to-analog converter for converting the master data set to an audio signal of the desired waveform and pitch. The ensemble effect is produced by transferring the words of the master data set to a second converter at the same pulse rate but having one value deleted or repeated once in the second set. Because the second set :has one less or one extra value in the set, the resulting audio tones from the two sets change phase with each successive cycle of the audio signals.

Abstract: A device for automatic tonal accompaniment in musical instruments equipped with a rhythm unit, the fundamental, the quint, or another tone related to a chord being held and/or the chord itself becoming available in a predetermined sequence in a selected rhythm, for at least one tonal key a chord sensor is provided at whose output a signal appears in the presence of a chord, and an associated switching device is connected thereto which in the absence of a chord switches the chord sensor to detection of individual tones.

Abstract: There is disclosed a trumpet incorporating rotary potentiometers which are controlled by means of circular wheels coupled to the shaft of the potentiometers. By rotating the wheel, the musician can vary the resistance of the potentiometer to thereby control the modulation and pitch characteristics of a synthesizer. The pitch of the trumpet is transduced by means of a pickup located in the mouthpiece of the instrument. The signal produced by the pickup is coupled to a pitch follower circuit whose output is coupled to the external input of a synthesizer module to hence use the actual pitch of the trumpet to vary the characteristics of the synthesizer. A transposition switch is located on the rear valve assembly and operates to control the transposition mode of the pitch follower. A glide switch is positioned beneath the transposition switch and is employed to control the portamento input of the synthesizer module.

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

Abstract: 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: Electrical circuitry for varying the relative distinctiveness between the lead and rhythm audio signals produced by an electrical guitar, or the like, according to the strength with which the musician picks the guitar strings. The rhythm signal is compressed in response to how hard the player strums or picks the guitar, while the lead signal is expanded as a direct function of rhythm signal compression. An electrical signal is generated from the rhythm signal for controlling the extent of compression and expansion of the audio signals.