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: A two-speed motor drive system for an acoustic rotor includes two simple, relatively inexpensive motors cooperatively arranged to drive the acoustic rotor at either a pulsato speed or a slower chorus speed, and also to provide automatic braking of the rotor from full pulsato speed to either slow chorus speed or to a fully stopped condition.

Abstract: A tone generator for use with an electronic musical instrument includes a binary counter operated by a binary comparator and a source of clock signals for incrementally advancing or decreasing the state of the counter from a first selected state to a second selected state. The states of the counter control a programmable divider which develops corresponding output tone signals. The counter produces multiple state changes between the selected states so that each individual state change results in a frequency change which is inaudible. The overall effect is to thereby synthesize a tone signal creating the illusion of a continuous pitch change between the pitches corresponding to the selected counter states. The source of clock signals includes a rate multiplier programmed according to the states of the counter to compensate system operation for insuring that similar musical effects defined by corresponding musical intervals are produced in equal time intervals.

Abstract: An automatic chord control system is readily incorporated in an electronic organ by means of large scale integrated circuit chips. The automatic chord control causes a chord or group of notes within an octave played on the lower manual keyboard to play through the upper manual voice in the octave below the lowest melody note being played on the upper manual keyboard. The proposed automatic chord control system has two operating modes. In the first mode, the notes transferred to the upper manual are generated in direct correspondence to the keys activated on the lower manual. In the second mode, the notes transferred to the upper manual are generated by a set of preset chords activated by single lower manual keys.

Abstract: An electronic organ or the like is provided with a plurality of frequency generators greatly less than the number of keys on the organ. Each generator is capable of producing an electrical oscillation of proper frequency for any musical note on the organ keyboard. The frequency generators are assigned to the desired frequency called for by depression of any key. Pulses are dropped, preferably in different numbers, from the frequency generators to avoid locking of oscillators in any musically desirable relationship to one another, including octave or harmonic relation.

Abstract: A musical sound controlling apparatus preferably incorporated into a music synthesizer type electronic music instrument and capable of generating a musical sound controlling signal in accordance with vocal signals or musical sound signals produced by musical instruments other than the music synthesizer type electronic musical instrument. The apparatus comprises a voltage-controlled filter whose frequency characteristics is controlled in accordance with a control waveform applied thereto and a control waveform generator which produces a control waveform varying with time in response to a trigger signal applied thereto. An external musical sound signal is applied to a switching circuit having a hysteresis characteristic through a rectifier circuit. The switching circuit is arranged to produce a stabilized trigger signal to be applied to the control waveform generator and have first and second different input switching levels for switching the output of the switching circuit.

Abstract: In a digital touch response circuit or touch signal processing circuit for producing a control waveform signal to control a musical tone to be produced in response to a player's finger touch on a key, digital touch data representing a player's instantaneous finger touch on a key is compared in a comparison circuit with digital output data from an operation circuit such as an adder circuit, which varies at a rate as the result of addition of a rate value to input data applied to the adder. A selection circuit is responsive to the comparison circuit to selectively couple the output data of the adder and the digital touch data to a temporary memory circuit such as shift registers. The output data from the memory circuit is coupled to the adder as the input data thereto.

Abstract: An echo effect in a polyphonic digital tone synthesizer in which a musical tone is repeated at a controlled repetitive rate but decreasing peak amplitude when a key is depressed. The tone is repeated until the peak amplitude decays to a predetermined level regardless of when the key is released. If the key remains depressed, the peak amplitude decay recycles so that an echo effect will be repeated. The echo effect is obtained on a plurality of overlapping notes that need not be keyed in unison. The echo control includes an echo envelope register which stores a control word for each key that is depressed. The control word includes bits coded to identify the current amplitude of the echo decay envelope. The value of the control word is decremented at a control rate to provide a decaying echo amplitude. An echo delay register stores a control word for each key depressed, the control word being incremented at a controlled rate.

Abstract: An electronic tone synthesizer in which a master data list of digital values representing the amplitudes of points defining the waveform of a musical tone are transferred to a digital-to-analog converter at a rate proportional to the pitch of the tone being generated. Noise is superimposed on the musical tone by means of a random binary signal generator which controls a circuit for modifying selected ones of the digital values as they are transferred from the master data list to the converter. Modification of the selected values may be by a right shift operation, a 2's complement operation, or by selective delay.

Abstract: A music synthesizer is disclosed. In the preferred embodiment, it cooperates with a tone source, such as a conventional or traditional music instrument, to form a synthesized output. The output can be voiced to provide music shaped and modified to a desired form. The circuit of the present invention uses an input signal supplied to a phase lock loop circuit coupled to a Walsh function generator providing Walsh output signals at frequencies corresponding to the input fundamental tone and a cascade of harmonics of the fundamental. The signals are selectively summed and weighted to form an output.

Abstract: An automatic arpeggio for a keyboard-operated instrument in which a tone generator is assigned to a key when the key is actuated, the fundamental frequency of the assigned tone generator being determined by octave and note data stored as a control word in a memory in response to operation of the key. On keying the different notes of the arpeggio chord on the keyboard and activating an arpeggio Load switch, a control word is loaded in the memory for each key of the arpeggio chord, the words being coded to identify the value of the note and the sequence number of the note in the arpeggio chord. The arpeggio chord control words in memory are transferred one at a time to a tone generator in a sequence according to the stored sequence numbers of the control words. Arithmetic means, in synchronism with an arpeggio clock, generates note sequence numbers by which the control words are addressed in memory. The note value is transferred to the tone generator together with octave information from the arithmetic means.

Abstract: An electronic musical instrument system comprising an electronic musical instrument body and a separate tone cabinet connected together by a cable. The electronic musical instrument body includes a plurality of tone coloring circuits to produce different musical tone signals, a musical tone signal selection circuit to select at least one of the output signals of these tone coloring circuits, and a musical effect selector; and the tone cabinet includes a musical effect imparting circuit to impart the selected musical tone signal or signals with a selected musical effect, a sound system having at least one loudspeaker connected to the musical effect imparting circuit, and a control circuit responsive to the musical effect selector for producing control signals to cause the musical effect imparting circuit to impart a selected musical effect to the selected musical tone signal or signals.

Abstract: In a digital musical instrument, timbre modulation is effected through the use of a digital magnitude comparator and associated digital logic. Selected note frequency signals and selected scale factors are compared in the digital magnitude comparator. Selected comparator outputs are applied to the associated digital logic in conjunction with a sample gating signal. This modulation results in a segmentation of the audio waveshape in accordance with the frequency signals selected for use in the comparator. Hence, choice of lower pitched frequency signals will result in a wider segmentation period, while choice of higher pitched frequency signals will narrow the segmentation period. Timbre modulation may be employed during note attack and/or decay.

Abstract: An electronic organ employing the technique of multiplexing at least the solo portion of the keyboard and which includes an automatic chord playing circuit which plays chords in the solo voices corresponding to the accompaniment portion of the keyboard in response to depression of one of a predetermined group of keys of the accompaniment portion of the keyboard. The organ includes circuitry for automatically sounding notes corresponding to the chord selected in the accompaniment portion singly and sequentially from a selected end of the solo portion of the keyboard to the opposite end thereof, and further selectable to begin at one end of the solo manual proceeding to the other end thereof and sounding in reverse order back to the first mentioned end of the manual. If desired, the arpeggio run may be terminated at a selected point on the keyboard short of either end thereof.

Abstract: Apparatus for chorus effect in an electronic musical instrument in which a passing circuit for a musical tone signal is obtained from a musical tone signal generator by operation of a key. The passing circuit is connected to a plurality of variable delay circuits which are individually controlled by a plurality of delay control signals generated by a delay control signal generator. The passing circuit for the musical tone signal has a format filter, as well as a keying signal generating circuit. An output terminal of this keying signal generating circuit is connected to a voice production initial stage change control signal generator. The latter control signal generator has an output terminal connected to the musical tone signal generator or the delay control signal generator.

Abstract: An electrical musical instrument having a digital circuit which automatically generates selected chordally related tone signals in response to manual selection of a root note. A root encoder provides a binary code representative of the root note in response to note selections, and an interval code generator automatically provides code signals having binary number values equal to the number of half steps from the root for a given interval. An adder arithmetically adds the root code and the interval code to generate a code for a chordally related note having both octave and note information corresponding to the automatically generated tone signal. In one mode of operation, the root code represents the root of the root-fifth pair of highest priority around the circle of fifths selected on a manual keyboard. In another mode, the root code is representative of a note selected on the pedal clavier.

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: A time-shared electronic musical instrument is provided with programmable wave-form generating and tone coloring circuits in order to maintain the musical characteristics regardless of pitch. The circuits comprise programmable keyers and wave-shapers, programmable envelope generators, programmable filters, and a programmable voicing selection circuit, in all of which certain characteristics of the output signal are tailored to the frequency of the musical tone.

Abstract: An electronic musical instrument comprises an automatic rhythm performance device, an automatic bass chord performance device and an automatic arpeggio performance device. Each device has its own start-stop control circuit and a control in/out terminal. When a device is start-stop controlled, a control signal appears at the control in/out terminal, whereas if a control signal is externally applied to the control in/out terminal, the device is start-stop controlled. The control in/out terminals of the respective devices are connected together by a common line so that a start-stop of one device causes the start-stop of other devices.

Abstract: A programmer for a music synthesizer including a keyboard and M independent voice modules (channels) and wherein the characteristics of each module are dependent upon K independent parameters, each parameter defined by an analog voltage level. The programmer is capable of storing N distinct programs, each program including information defining K parameters for each of M modules. The programmer is comprised of a common set of K potentiometers which are coupled through an analog to digital (A/D) converter means. The output of the A/D converter means is applied selectively either to a digital memory for storage at a location defined by operator controlled switches or through a digital to analog (D/A) converter means to the voice modules. Alternatively, information applied to the D/A converter means for application to the voice modules can be derived from the digital memory.

Abstract: A circuit intended for use with electronic organs and, more specifically, with those electronic organs in which the keyboard switches are multiplexed, and which circuit provides a method for automatically sounding in succession either the natural notes (white keys) or the sharped notes (black keys) to create a glissando effect, beginning at either the upper, or lower, end of the solo manual and continuing down, or up, the manual at least until the note which is depressed by the player is reached. This simulates the effect of the organist running his finger from one end of the manual partially down, or up, the manual and reaching the previously mentioned depressed key.

Abstract: A digital organ or like electronic musical instrument of a real time processing system which produces musical notes by synthesizing weighted square waves and applying them to a digital filter of a transfer characteristic controlled for each square wave. Key information from a keyboard is detected by a key code generator having a key switch matrix in which key switches are grouped into a plurality of blocks. The key switches are scanned for each block and when one or more key switches of the block are closed, the scanning is stopped until after the closure information is sent out as binary coded information to a key code data assignor in accordance with priority. The key code data assignor applies envelope control signals to an envelope generator and an N-degree square wave generator. The envelope generator is a cyclic digital filter whose filter constant is controlled to provide desired envelope waveshape data for input to a multiplier.

Abstract: A digital electronic musical instrument which produces musical notes by approximately reproducing a waveshape based on information of points of extremal values on a musical waveshape, storing the approximate waveshape after sampling it with the number of the frequency at which the notes are to be produced and reading out the stored waveshape with a predetermined clock.

Abstract: A CPU of a computer, or preferably a so-called microprocessor controls the tone waveshape generation. A tone generator unit, an instrument keyboard unit, a tone quality control unit are connected to a common data bus to which the CPU and the associated memories are also connected. Thus, the tone generator unit may be considered as a terminal unit of a computer system. Hence, the freedom in selecting the algorithm for generating a waveshape and the freedom in selecting and changing the parameters related to the waveshape generation are substantially increased. And therefore a gradually changing waveshape is very easily generated in one embodiment of this invention.

Abstract: A driver circuit for a tone generator that is adapted to cause the tone generator to produce a pleasant sounding chime. The circuit comprises high and low frequency oscillator circuits whose decaying sawtooth type outputs are summed and modulated to produce the desired chime effect.

Abstract: An electronic musical instrument including key switches which are connected in a matrix of twelve note lines times six octave lines. The note lines are scanned cyclically at a high speed and the octave lines are detected one by one cyclically to determine the closed key switches. Everytime a closed key switch is detected, the scanning operation pauses for a predetermined period of time and a note indicating signal is delivered. The note indicating signal causes the production of a tone signal of that note for a predetermined octave. The number of the detection cycles is counted by a counter, and the detection of the same note in the next cycle causes the production of a tone signal of the same note for the next octave, the counter causing the shifting of the sounding octave. The octave shifting is repetitively carried out upward or downward or reciprocally within a range of certain octaves. Thus an automatic arpeggio performance is realized.

Abstract: An information transmission system for N information signals for the transmission of either N parallel signals, or of only one information signal from a signal range of M signals with M.ltoreq.N at the upper or lower range boundary. N signal transmission gates are provided which can selectively be switched effective, these gates being connected through by means of control signals either for N information signals or for the signals at the upper or lower boundary of a signal range.

Abstract: An electronic musical circuit simulates the sound of a wire brush rotated around the head of a snare drum by differently amplitude modulating and bandpass filtering in separate channels a noise signal derived from a suitable source and summing the modulated and filtered noise signals from the separate channels to produce a sound imitative of the rhythmic variations in pitch and amplitude produced by wire brush rotation on the head of a snare drum.

Abstract: The present invention is an arpeggio system for use in a musical instrument having a multiplexed keyboard, wherein operated playing keys are represented by cyclic pulses in corresponding time slots in a serial time division multiplex data format, connected over a single bus to a multiplexed pitch generator system for producing tones at pitches corresponding to the time slots in the serial data stream in which the cyclic pulses representing operated playing keys appear. The arpeggio system is connected in the serial data path in repeater fashion so as to be operated under control of the serial data stream received from the keyboard to selectively retransmit cyclic pulses in the serial time division multiplex data format to the pitch generator system.

Abstract: A pitch bend apparatus for electronic musical instrument having a voltage-controlled oscillator that works as a tone generator is provided with a first variable resistor for operating the pitch bend as well as a second variable resistor for setting a varying width of pitch bend or a maximum amount of pitch deviation. The varying width of the pitch bend is controlled by connecting the first and second variable resistors into an amplifier circuit to control the gain thereof, or by controlling the voltage applied to the first variable resistor by means of the second variable resistor.

Abstract: A distortion sound effects circuit producing an output signal corresponding to an input signal but containing one of four selected types of distortion. A compressor which includes a voltage-controlled amplifier first compresses the audio input signal within preselected limits, and the distortion operations are performed on the compressed audio signal to advantageously render the subsequent distortion operations insensitive to gross amplitude fluctuations of the input signal. The compressor includes means for full-wave rectifying the compressed audio signal. The full-wave rectified signal is provided as a distorted output signal containing hard-even distortion of the type commonly achieved by severely, asymmetrically clipping a signal. A distortion circuit includes single voltage controlled square-low amplifier to which the compressed audio signal is applied performs the other three types of distortion.

Abstract: An electronic musical instrument comprises a circuits for generating two kinds of voltages of tone pitch voltages and control voltages both of which correspond to respective keys but are independent of each other. In the control voltage generating circuit, a voltage applied to a single voltage division circuit is switched in its value and polarity according to octave information. Output of this voltage division circuit is selectively delivered out according to note name information thereby to control musical elements in a musical tone.

Abstract: In an electronic musical instrument, the keys of a keyboard are divided into a plurality of groups by octaves, and a wave generator is provided with a memory for storing constants corresponding to musical tone frequencies to be generated according to the notes includes in a desired group out of the plurality of group, an accumulator for repeatedly adding the constants read out of the memory, and a bit position shifting circuit for shifting the bit position of the data produced by the accumulator according to the octave range of a note to be produced, thereby to obtain the data varying repeatedly according to the frequency of a note to be produced, and to reduce the storing capacity of the memory when compared to the number of keys.

Abstract: A tone synthesizer generating a marimba effect in which two percussion notes are sounded alternately an ocatve interval apart, simultaneously with and in response to the playing of a sustained note by depressing a key. The marimba tones are synthesized by alternately, at controlled intervals, calculating master data lists of the amplitude values representative of points on the waveforms of the two marimba tones and converting the respective master lists to analog waveforms by feeding the data in series to a digital-to-analog converter. The master data list for each tone in calculated by multiplying a set of coefficients for each tone with a set of sinusoid values. The coefficients correspond in value to the relative amplitudes of the harmonics of the tone. By sounding one set of coefficients with the odd number harmonics all equal to zero, the two resulting tones sound an octave apart.

Abstract: A control system for an electronic music synthesizer includes a circuit responsive to the keying of a musical instrument for producing a binary coded signal. This signal is converted to an analog signal, for application to a music synthesizer. The analog voltage may be modified, for transposition or for portamento effects. The coding circuit may produce trigger and gate voltages for the synthesizer, whereby blowing of the musical instrument, if a wind instrument is employed, is not necessary. Alternatively, the trigger and gate pulses for the synthesizer may be developed from the output of the transducer coupled to the instrument.

Abstract: A multichannel recording medium storer which samples the time course of notes produced by an instrument and an address for each of these samples. An interchangeable keyboard transmits a signal or signals to an electronic computer as to which note or notes are to be reproduced. The electric computer reads the note or notes to be reproduced from the recording medium and from the sample produces a faithful reproduction of the sustained note or notes. The result is available for recording on one channel of the recording medium or for reproduction on a speaker. The instrument is useful for the preparation of musical compositions and for educational purposes and demonstrations.

Abstract: In an electronic musical instrument comprising a keyboard including a plurality of keys, a frequency information memory device for storing frequency informations corresponding to respective keys, a plurality of musical tone forming means including a waveshape memory device for forming musical tones in response to the output of the frequency information memory device, and a shift circuit interposed between the frequency information memory device and the musical tone forming means for effecting a footage change of an octave unit, there is provided a preset circuit for applying a plurality of preset footage signals to the shift circuit and for applying another preset signals which are necessary to form musical tones to the musical tone forming means.

Abstract: In an electronic organ system having a plurality of tone generators one for each note to be sounded, and a time constant circuit for establishing first and second decay characteristics for each note, the first of which has a longer decay period than the second, a key-down detector for sensing the operated condition of any key of the keyboard, and a circuit operative in response to the key-down detector to cause the sounded notes to have the longer decay characteristic so long as any key of the keyboard is depressed and to cause the sounded notes to have the shorter decay characteristic when all keys are released, for producing a pseudo-reverberation effect.

Abstract: An electronic musical instrument in which a keyboard circuit generates scale tone voltage signals corresponding to depressed keys of a keyboard. Plural musical tone signal forming sections are connected respectively to plural output terminals of the keyboard circuit which has plural series-connected resistance circuits. Each of the resistance circuits has series-connected resistances which, in turn, are connected at one end to an electrical source. Key-switches are provided to move with the keys of the keyboard, and these key-switches are connected so that when plural keys are simultaneously depressed according to a chord, respective scale tone voltage signals corresponding to the respective keys are generated at respective connecting points of the resistances in the series-connected resistance circuits, and they may be respectively transmitted from the plural output terminals.

Abstract: There is described a tone generator in which waveform amplitude data is generated from a table of sinusoid values in an addressable memory by changing the addresses as a function of time in a periodic or sinusoidal manner. The effect is to produce a sequence of sinusoidal values from the table which correspond to a series of points on a frequency modulated carrier signal. By making the effective modulation frequency equal to the carrier frequency, the resulting frequency modulated signal corresponds to a carrier with side bands that correspond to harmonics of the carrier. The relative amplitudes of these harmonics can be varied as a function of time to produce the sliding formant effect of a synthesizer.

Abstract: A system for the selection and phase control of humbucking coils in electromagnetic guitar pickups to permit the musician to easily select different sounds using digital memory means for storing different combinations of gate control bits to select the pickup coils to be used, the phase of the coils selected and the output level of the selected coils combined. A three-way switch is used to count up, count down or hold a memory address for selection of a combination. The address is displayed for verification. Memories may be prestored ROMs, or alterable RAMs in which write enable control is controlled by a three-way switch. Three address counters may be provided to permit the musician to quickly select from three predetermined combinations through operation of a three-way switch.

Abstract: A tone synthesizer in which a musical tone of selected fundamental frequency is generated with a resonance effect at selected harmonics of the tone. The resonance effect is produced by adding an amplitude modulated carrier signal to the musical tone, the carrier signal being modulated by a signal having the fundamental frequency of the musical tone and the carrier frequency being an integral multiple of the fundamental.

Abstract: An electronic musical instrument comprises first and second voltage-controlled frequency-variable oscillators responsive to application of a pitch determining voltage signal from a keyboard circuit to produce first and second audible frequency signals, respectively. The second audible frequency signal is coupled to the first voltage-controlled oscillator to produce a frequency-modulated tone signal to be sounded in which the first audible frequency signal is frequency-modulated with the second audible frequency signal. The content of harmonic components in a musical tone can be increased by sideband components resulting from frequency modulation. The second audible frequency signal may be amplitude-controlled to be proportional, in amplitude, to the magnitude of pitch determining voltage signal, amplitude-modulated with a time-varying control waveform, and/or waveform-modified to provide desirable modulation effects.

Abstract: An electronic musical instrument of a type having automatic performance functions includes means for switching a tone production mode to another tone production mode without stop of tone production when the automatic performance is stopped, so that a smooth continuation of a manual performance after the automatic performance is ensured. When an automatic arpeggio performance producing a tone of a percussion type envelope is stopped, the tone envelope is switched to a sustain type envelope and the tone is kept produced as long as the key for the tone is kept depressed. In an automatic bass/chord performance producing intermittent bass tones and chord tones, bass tones and chord tones are continuously produced after stopping of the automatic bass/chord performance.

Abstract: A touch operated capacitive switch for altering electrical signals controlling the mode of operation of an electronic musical instrument. The switch comprises a thin laminate having a non-conducting lamina sandwiched between a conducting touch electrode and a conducting guard electrode, each electrode having an electrical connector for connecting the switch to alternating electrical signals having substantially the same phase and amplitude to reduce the capacitance between the touch electrode and points of ground potential located in or on the instrument for increasing the sensitivity of the switch. The switch is non-conductively secured to the instrument with the guard electrode facing the instrument, such that the capacitance of the switch may be altered by touching the touch electrode.

Abstract: An electronic musical instrument is of a type wherein musical tone waveforms are stored in a memory as their sampled amplitudes and sequentially and repetitively read out to constitute tone waveforms. A key depression brings forth key code in a digital representation. This key code is used for reading out frequency information from a frequency information memory. The frequency information is accumulated to make an address signal for reading out the waveform memory.When a key is depressed, a counter starts counting and opens a gate for a predetermined period of time. The gate passes a code representative of an interval of a grace note with respect to the note of the depressed key (i.e. principal note) to an addition and subtraction circuit for addition or subtraction between the key code and the code representative of the interval for the grace note. Accordingly, the key code is modified and the desired grace tone is produced.

Abstract: A device for producing a chorus effect in an electronic musical instrument. An electronic delay circuit and a non-modulating amplifier means are coupled in parallel and the outputs are mixed in a mixing amplifier. A carrier oscillator is coupled to the delay circuit for controlling the time delay of the delay circuit according to the frequency of its output, and normally oscillates at a relatively high frequency in the range of 80-100 KHz. A modulation signal generator is coupled to the carrier oscillator for frequency modulating the carrier oscillator toward lower oscillating frequencies, and a control signal generator is coupled between the input to the delay circuit and the modulation signal generator for detecting the musical tone signal input to the delay circuit and producing a control signal only when a musical tone signal input is detected.

Abstract: A programmable rhythm unit is disclosed for electrically simulating sounds of a plurality of rhythm instruments being played in selected ones of a plurality of different rhythmic patterns. A variable frequency oscillator cooperates with a counter/divider and decoder circuit to provide a predetermined number of beats or pulses per measure at a tempo which may be varied by the user. Also provided is a plurality of keyed audio circuits which each produce a characteristic burst of output signals that simulate the audible output or voice of a corresponding rhythm instrument. Switching means are provided whereby the user can select any of the voices to play at any beat position. In addition an alternate beat pulse source is provided which can be selected by the switching means to play any of the voices at a particular beat position every other measure. A pseudo-random generator is also included which may be selected to play any of the voices at a random beat position in each measure.

Abstract: An electronic musical instrument comprising a plurality of tone forming systems having mutually different tone production modes. One of such tone forming systems can produce a tone continuously while another of such systems can produce a tone intermittently. Further, in a case where a plurality of tones are to be produced, one of such systems can produce these tones intermittently one tone after another while another of such systems can produce these tones simultaneously and intermittently. By producing tones from such systems of different tone production modes, an intricate musical tone effect is obtained.

Abstract: Apparatus for converting the relatively rapid rise time, relatively long fall tone envelopes of a music source output to envelopes having relatively long rise time and relatively rapid fall time and for also varying the frequency of the tone in the nature of the Doppler effect of an accellerating source provides the modulation input to cascaded phase and amplitude modulators fed by the music source.