Abstract: Disclosed is a digital arpeggio system for an electronic organ that through the use of digital techniques permits arpeggios, note sequences as well as strum, multi, organ, and normal modes of operation to be played automatically. Two counters scan by counting through an 8.times.8 matrix of 64 words covering the 61 notes of an organ in rapid sequence upon the playing of one or more organ keys. Each word is fed to a corresponding one of 61 decoders, one for each note of the keyboard. If a corresponding key has been played, the decoder provides a signal to a corresponding pulser circuit which enable a corresponding keyer to transmit an audio signal from an audio oscillator corresponding to the played key to an output system and loudspeaker. The two counters are stopped by a clock control while the note is sounded and then the counters are enabled by the counter control to continue counting through the matrix until the next actuated key is located.

Abstract: A keyboard controlled just intonation computer for electronic organs which automatically responds to correct the larger tuning errors of equal temperament as each interval or chord is played. The logic circuit for this purpose has twelve inputs corresponding to the twelve notes of the chromatic scale. The logic circuit can be interfaced with the keyboard by utilizing keyer voltages from octavely related key switches fanning into each input of the logic circuit through a diode branch circuit. Each of the twelve master oscillators of the organ has a two input tuning means adjusted to lower the frequency of the master oscillator by one seventh of a semitone if one input is energized by an output of the logic circuit or by three tenths of a semitone if the other input is energized. The smaller pitch shift is required for the top notes of major thirds or major sixths, or for the bottom notes of minor thirds or minor sixths.

Abstract: An organ circuit and method of operation in which a detecting system detects combinations of keys played in the accompaniment portion of the keyboard arrangement of an electronic organ and through associated circuitry causes a respective chord to sound regardless of the particular position of the depressed keys or the particular chord inversion represented by the depressed keys.

Abstract: A digital keying system for an electronic musical instrument, such as an electronic organ, comprises a digital percussion generator which synchronizes the operation of a variable attentuator with the zero crossings of a sine wave signal applied to the input of the attenuator from a waveform generator. Pulses from a rhythm generator are applied to a coincidence gating circuit along with pulses corresponding the zero crossings of the sine wave signal from the waveform generator to synchronize the stepped operation of the variable attenuator with the zero crossings of the sine wave signal applied to it.

Abstract: A manually played electrical musical instrument of the electronic type in which simultaneously with selection and playing of a melody tone (note) a predetermined pattern of harmonies are also selected in such manner that at least five of the harmonies selected for the appertaining tone are mutually different. The instrument also includes generation of rhythm sound effects which permits programming of predetermined rhythm patterns defining the times of occurrence of predetermined rhythm sounds in a sequence of a predetermined number of beats, and generation of different bass tones according to a sequence of notes.

Abstract: An electronic musical instrument incorporates a single integrated circuit chip for performing a variety of logical operations for the production of chords and various accompaniment signals automatically, in response to depression of one or two keys within a related portion of the keyboard of the instrument. A multiplexer is employed, in association with the keyboard, to produce a train of signals in response to depression of one or more keys, and one or more function control switches; certain ones of these signals are used to address a plurality of read only memory devices for the generation of the several components needed for the mode of operation which is selected. In an automatic chord mode, a chord is selected automatically, corresponding to an operated key of the keyboard. The chord components include the root, the third (which may be selectively minored), the fifth, the sixth and the seventh (which can be selected or not).

Abstract: The electronic musical instrument is provided with a musical tone signal generating unit for generating a musical tone signal having a tone pitch corresponding to a depressed key, a self-running counter for counting a multibit digital quantity, a latch circuit for latching the output of the counter when supplied with a pulse signal representing the depression of a key, and modifying means responsive to the output of the latch circuit for modifying the musical tone elements, that is the pitch, color and volume of the musical tone signal generated by the musical tone signal generating unit.

Abstract: A programmable voice characteristic memory system for programming any number of different specifications in an electronic digital organ. Digital information which defines voice characteristics in an electronic digital organ is stored in a read-write specification memory. Voice characteristic information may be selectively written into the specification memory from an external data inputting device such as a punched card reader or from an external non-volatile read-write memory such as a magnetic tape. Information stored in the specification memory may be transferred to and recorded on the external non-volatile read-write memory for permanent storage and future use. Voice characteristic information stored in the specification memory may also be accessed by the digital organ to generate musical tones in conventional fashion.

Abstract: The bass note generation system provides one of several different types or styles of bass-line accompaniment for the organist. A chord pattern detector receives signals on keying lines corresponding to keys depressed by the instrument player and attempts to recognize a normalized chord pattern. A counter tracks the operation of the chord pattern detector and provides an output corresponding to the alphabetic note of any recognized chord. If the chord pattern is recognized, the output of the detector and the output of the counter address a normalized and preprogrammed bassline pattern memory. The digital value of the bass note stored in the memory and the outut of the counter are serially added to transpose the normalized bass note to the appropriate musical key and applied to a decorder-keyer circuit at selected time intervals in a musical measure for providing a precomposed musical bassline output.

Abstract: This invention relates to an electronic musical instrument which comprises a waveshape computation cycle, a waveshape transmission cycle and an envelope load output. In the waveshape computation cycle, a musical waveshape is obtained in the form of the accumulation of the products of the nth powers of the fundamental frequency of a cosine wave and coefficients A.sub.n indicating harmonic components of a musical note in certain relationship.

Abstract: In order to simplify the intricate wiring in known automatic bass chord systems and to reduce the number of separate decoders used therein for all chords of each key, an apparatus is provided which allows the use of only one decoder per chord type. When a chord is held one bit is applied to the inputs of a first 12-bit shaft register which correspond to the tones of the chord, after which all bits are shifted further by an HF clock pulse until this chord pattern has arrived at those outputs of the 12-bit shift register which, with the inputs of the decoder which corresponds to the chord being held, are assigned to a single pre-selected tonality.

Abstract: Keyboard apparatus for an electronic musical instrument in which a particular code is assigned to each of keys of the keyboard and which is provided with a multiplexer circuit for detecting the depression of the key corresponding to an input code, means for sequentially generating the codes of the keys, memory means for storing the codes, a comparator circuit for comparing the outputs from the memory means and the code generating means to provide a coincidence signal when the both outputs are coincident with each other, a cycle control circuit for controlling a key ON cycle and a key OFF cycle in distinction from each other, and gate means for selecting the output code from the code generating means and the code of the memory means with the key ON cycle and the key OFF cycle to output to the multiplexer circuit. In the key ON cycle, the multiplexer circuit detects that the key having not been depressed yet is newly depressed, and stores it in the memory means.

Abstract: In a chopper keyer electronic organ system, a sampling network samples the drawbar inputs to the chopper keyers in order to provide a separate channel of percussion. The drawbar lines for one or more of the footages are sampled and the sample signal is amplified and shaped to provide touch envelope percussion in addition to the sounding of the chopper keyer outputs. Alternatively, the chopper keyer outputs may be disabled and separate voicing such as for piano, harpsichord or steady tones provided via the drawbar sampling circuitry.

Abstract: A sophisticated polyphonic instrument providing both additive and subtractive tone synthesis capabilities for generating a myriad of timbres, yet occupying a volume comparable to a toy accordion, is described. The unusually broad capabilities, for a small size synthesizer, is achieved through use of the novel LSI oriented circuits described in copending applications entitled "Electronic Organ With Multi-Pitch Note Generators", Ser. No. 610,733, filed Sept. 5, 1975, and "Automatic Arpeggio For Multiplexed Keyboard", Ser. No. 675,834, filed Apr. 12, 1976. The small size is made possible by use of LSI circuits in conjunction with a novel note keyboard arranged to select any note of the chromatic scale over a five octave range with only five keys, played by the right hand, and a novel chord keyboard, played by the left hand, arranged to select any one of ten chords based on the selected note as its root. The chord may be selected in its fundamental or either of two inverted forms.

Abstract: An automatic musical instrument in which a chord discrimination and a musical performance circuit are arranged so that a comparator with multiple input terminals on one side, is connected to a memory circuit having multiple basic types of chords memorized. The comparator has multiple input terminals on the other side connected to key switches through a shift register. The comparator, furthermore, has a control electrode connected to a clock pulse generator which is connected, in turn, to multiple input terminals of the memory circuit, by way of two counter circuits. The latter have multiple output terminals connected, respectively, to two latch circuits. The comparator has an output terminal connected to control electrodes of the latch circuits. The musical performance circuit has a decoder connected to multiple output terminals of one of the latch circuits.

Abstract: A key code generator for electronic musical instruments which has a switch matrix circuit having a plurality of switches disposed at the intersections of two sets of buses, means for simultaneously applying signals to the switch matrix circuit from one of the two sets of buses to derive outputs from a plurality of blocks into which the buses of the other set are divided line by line, a memory for detecting the blocks that even one switch is in the on state from the bus outputs of the switch matrix circuit and temporarily storing signals of the detected blocks, a first priority selector for selecting block signals in a predetermined order of priority from the bus outputs and sequentially outputting the block signals with a predetermined clock pulse, means for inhibiting the block detecting operation during outputting from the first priority selector and applying the selected block signals to the buses of the detected blocks to sequentially scan only the detected blocks, a second priority selector for selecting

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

Abstract: An arpeggiator for an electronic organ, comprising a source of ramp voltage having selectively a slowly ascending and a slowly descending section or only a slowly ascending section followed by a rapid reset, an accordion-like voltage divider for said ramp voltage consisting of a cascade of diodes, each calling forth one of a group of three tone signals when conductive, or no tone signal if short circuited, circuits for determining which diodes shall be conductive and which short circuited according to which keys of an organ are actuated, the ramp voltage peaking when all conductive diodes have been ascendingly scanned by the ramp voltage, each conductive diode when scanned by the ramp voltage falling forth a gating signal for one of the tone signals called for by the actuated keys, in orderly sequence of tone signals.

Abstract: In an electronic musical instrument wherein waveshape F(x, y) is computed and the resultant waveshape is converted to a musical tone, computation of said waveshape F(x, y) is carried out in accordance with either one of the following equations: ##EQU1## WHEREIN: F(X), F(Y) REPRESENT MATHEMATICAL FUNCTIONS OF TIME, RESPECTIVELY; AND N REPRESENTS AN ARBITRARY INTEGER.

Abstract: An automatic rhythm generator of an electrical musical instrument including a rhythm pattern generator for rhythmically selecting for actuation different ones of a plurality of instrumentation circuits to be sounded and a strobe pulse generating circuit for establishing the appropriate pulse width of a drive pulse needed by each instrumentation circuit for proper actuation thereof. The rhythm pattern generator circuit selectively enables a plurality of drive gates respectively associated with the plurality of instrumentation circuits during selected ones of a succession of periodic rhythm cycles in accordance with a predetermined rhythm pattern. The strobe circuit is synchronized with the rhythm pattern generator and generates during each rhythm cycle a plurality of strobe pulses on a corresponding plurality of outputs respectively associated with the plurality of instrumentation circuits. Each of the strobe pulses has a width preselected for the instrumentation circuit with which it is associated.

Abstract: A fully digitalized function-of-time generator suitable for use as a tone envelope generator in a digital electronic musical instrument, comprising: a clock pulse generator for generating a clock pulse at a selectable rate; a gate enabled at each arrival of the clock pulse; a single-stage binary shift register for successively shifting out its contents as a digital word representing the instantaneous values of a desired function of time synchronously with the clock pulse; a digital subtractor; a digital multiplier; and a digital adder, all of these members being interconnected to each other to be operative so that the output of the register is subtracted from a first set value representing a digital word, the resulting difference being multiplied by a second set value representing a digital word, the resulting product being added to the output of the register via the gate, so that the resulting sum is loaded into the register.

Abstract: A rhythm selection switch arrangement mounted on the operation panel of an electronic musical instrument. The switch arrangement comprises a plurality of on-off push changeover switches arranged successively and a changeover push switch disposed adjacent to the two-position push switch nearest to the player of the electronic musical instrument. The two-position push switches are to select a rhythm, and the push switch is to control the standard or variation mode of the selected rhythm.

Abstract: An electronic musical instrument comprises a waveshape memory delivering out digital value samples of one cycle of a certain waveshape, and a loop circuit including a filter and a shift register. The digital waveshape values read out from the waveshape memory is caused to circulate at a predetermined rate of time in the loop circuit. A waveshape taken out from the loop circuit varies as time lapses, and is utilized as a musical tone.

Abstract: Circuitry in an electronic organ for electronically storing a series of signals corresponding to depressed keys depression and for recalling the stored series in response to player commands.The circuit allows the player to play accompaniment chords of a piece of music alone and at any desired pace, and then while manually rendering the righthand, or solo, portion of the music. The chords are played by simply depressing a single control button whenever the next chord in the stored series is required.A further feature of the invention is the ability to store sets of switch or tab or other selector element settings for later recall. The selector element setting storage circuit enables the player to switch tab settings during storage of chords, while storing the patterns in the order in which they will be desired.

Abstract: In a keyboard electronic musical instrument such as an electronic organ, an electro-mechanical memory device for holding in the down or actuated position one or more simultaneously depressed accompaniment chord and bass playing keys after the finger pressure from the instrument player is removed. The signal representing the note or chord associated with the depressed key or keys is sustained as long as the keys remain latched down. A plurality of keys of the lower or accompaniment manual are adapted to be retained in the depressed position and operate as part of the electro-mechanical memory device. When a key or group of keys are latched down, the depression by the instrument player of another key releases the previously retained keys but the newly depressed key is latched down. The electro-mechanical memory also operates in conjunction with the touch mode of the automatic rhythm unit to provide a rhythm signal when the accompaniment keys are retained in the depressed position.

Abstract: A pedal tone generator for an electronic musical instrument, such as an electronic organ, having the capability of automatically producing bass rhythm patterns based on a tonic note, includes a memory for storing a plurality of rhythm patterns which has a plurality of outputs for producing a predetermined pattern sequence for each of the notes of the diatonic musical scale, and a circuit for producing signals indicative of which of the pedal keys, usually thirteen, is operated by the instrumentalist. The pedal key signals are binary encoded to produce a plurality of code words each unique to the tone of one of the keys, and each of the outputs from the memory is also binary encoded to be uniquely represented by one of a corresponding number of code words. Code words representing a depressed key and the note instantaneouly being "played" by the memory are added to produce a coded digital signal representative of the sum in the duodecimal system of counting.

Abstract: Upon key depression, there is produced a phase progress signal in digital representation which varies by an increment predetermined in accordance with the frequency of the note designated by the depressed key. The phase progress signal is subjected to a coordinate conversion and squaring operation to provide downward opening parabolic curves and upwardly opening parabolic curves, which are alternately connected at their open ends to produce an approximate sinusoidal waveform as a digital tone signal. The digital tone signal is multiplied by a digital envelope signal to produce a keyed musical tone signal.

Abstract: An arrangement for providing an automatic musical performance in which a digital signal indicating a root tone is obtained by depression of a key, and is added in sequential order with digital signals obtained from a memory circuit. The latter is driven by output pulses of a rhythm pulse generator. Binary coded signals from the outputs of the adder, open and close plural gate circuits interposed in plural tone source signal passing circuits. One decoder is provided at the plural output terminals of the adder, and plural output terminals of that decoder are connected to control terminals of respective gate circuits. The decoder converts the binary code signals into address signals. An additional decoder may be provided at the output of the adder for converting the output binary code signals to binary-coded duodecimal codes.

Abstract: For reiteration of percussive sounds in an electronic organ there is provided a circuit for generating pulse signals for reiteration control which are "on" for much longer periods than they are "off", thereby substantially reducing the chance of an organ key being actuated when the control signal is in its "off" condition. The circuit is so arranged that playing of an additional key at a time when one or more other keys are being held has no effect on the reiteration of the sound produced by the held keys. The circuit generates four control signals which are connected such that each controls three notes in a given octave on the keyboard, a different three in successive octaves, such that when normal intervals (e.g., thirds, fourths and fifths) are played, the effect of random reiteration control is produced.

Abstract: An electronic organ in which rhythmic note patterns can be played on the accompaniment manual by the depression of a single key. The organ includes a source of rhythmic pulses which may, for example, be taken from the pulse source of a conventional rhythm unit. The accompaniment manual of the organ can be played in a conventional manner or it can be adjusted to play rhythmic note patterns during which the normal playing of the accompaniment manual is disabled and only a selected group of accompaniment keys, preferably a group of adjacent keys at the left end of the keyboard, are enabled for controlling the pattern to be played. When the organ is adjusted for pattern playing, each of the aforementioned group of keys is operable, when depressed, to initiate the playing of a pattern in conformity with stored memories and in further conformity with the respective one of the pattern controlling keys which is depressed.

Abstract: A rectangular waveform signal reproducing circuit for electronic musical instruments which is composed of a first charge-discharge circuit having a relatively small charge time constant and a relatively large discharge time constant for charging and discharging positive components of a monophonic signal, a second charge-discharge circuit having a relatively small charge time constant and a relatively large discharge time constant for charging and discharging negative components of the monophonic signal, first comparing means for comparing the monophonic signal with the output from the first charge-discharge ciruit to produce a first compared output representing that the level of the former is larger than that of the latter in the positive direction, second comparing means for comparing the monophonic signal with the output from the second charge-discharge circuit to produce a second compared output representing that the level of the former is larger than that of the latter in the negative direction, and a fli

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: An organ circuitry for providing fill notes and a method of operating the organ in which a circuit is provided which adds fill notes automatically in the multiplexed solo manual of an electronic organ, by detecting the first pulse encountered by the multiplexer during a scan of the keyboard and developing further pulses in conformity therewith but pertaining to notes within the octave beneath the note corresponding to the detected pulse, and combining the pulses on a data stream which is demultiplexed for actuating keyers.

Abstract: A noise suppression circuit for digital tone generator in which a table of digitized data points are converted at a rate controlled by the fundamental frequency of the tone being generated. The suppression circuit determines the difference between each pair of successive data points and increments the prior data point in a succession of equal intermediate steps proportional to said difference. The data points together with the succession of incremented values between said data points are converted by a digital-to-analog converter at a converter rate equal to or greater than the maximum rate at which each data point is incremented.

Abstract: In an electronic musical instrument, a tone source circuit provides tone signals of audio frequencies representing respective notes in a musical scale. A keyboard circuit provides a keying sequence pulses each existing at such a time slot of time sharing at an ultra-audible rate as is assigned to each of keys being depressed. The tone signals and the respectively corresponding keying sequence pulses are AND-gated respectively and then OR-gated commonly to produce a combined tone signal. The keying sequence pulses are obtained by sequentially scanning all the keys in the keyboard in one sequence, or may be equivalently obtained by scanning the same named keys in different octaves simultaneously and AND-gating with octave representing pulses. Or the octave representing pulses may be omitted by separately processing tone signals octave by octave. The system is suitable for digitalization and for production in IC configuration.

Abstract: An electronic organ having solo, accompaniment, and pedal keyboards, or manuals, and adjustable into different modes of playing for at least the accompaniment keyboard.In a first playing mode, the accompaniment keyboard plays in a conventional manner with each key of the keyboard which is depressed actuating a respective keyer.In a second selectable playing mode, the keys of the accompaniment keyboard are disabled for actuating keyers in a conventional manner and, instead, a selected group of the keys, referred to as "chord playing" keys, are made effective for playing chords by having each of the chord playing keys actuate a respective group of keyers while the key is depressed.In a third playing mode, the keys of the accompaniment manual are disabled for actuating respective keyers and, instead, the same group of "chord playing" keys referred to above are enabled for actuating the keyers pertaining to respective chords singly, or in groups, sequentially at predetermined time intervals.

Abstract: The disclosure describes an improved digital oscillator for use in an electronic musical system capable of converting electrical tone signals into corresponding sound waves. The oscillator includes an adder, accumulator and multiplexer for selectively transmitting either a divisor number or increment number to the adder. The oscillator cyclically performs incrementing operations by using the increment number over a variable range established by the divisor number at the beginning of each cycle. When the modulus of the adder is exceeded, the adder generates a carry pulse and a remainder. The divisor is then added to the remainder before the incrementing operations begin again. A digital calculator automatically calculates the proper values of the increment and divisor numbers so that the carry pulses occur at a predetermined frequency.

Abstract: A register arrangement is provided for an electronic musical instrument (such as an electronic organ) whereby the various functional units of the instrument are actuated by electronic selector switches each one of which in turn has a control conductor to which control voltage can be applied by a register assembly either individually or as part of a preselected grouping of functional units.

Abstract: An arpeggio circuit for an electronic organ employing digital encoding, decoding and code conversion techniques to semiautomatically generate an arpeggio effect composed of tone signals having an octaval relationship and corresponding to selected note keys held down on an accompaniment keyboard. The rate of generation and order of the arpeggio tone signals is controlled by means of a plurality of manually actuatable arpeggio control switches. A plurality of individually identifiable control signals are sequentially generated in response to sequential actuation of the plurality of control switches. The control signals are binarily encoded. Tone signals provided by a set of tone generators are selectively associated with appropriate ones of the encoded control signals by a tone selector circuit which provides the selected one of the tone signals to an arpeggio output tone signal generating circuit when the associated encoded control signal is being generated.

Abstract: A musical instrument which comprises (i) a portable transmitter unit, (ii) a receiver unit, and (iii) a standard or modified piano, electronic organ, or other keyboard musical device. The transmitter unit has sixty keys, each of which corresponds to a key of the remote piano, organ, or other keyboard musical device, and also has eight auxiliary switches for controlling the receiver and auxiliary functions of the musical device to be remotely played. The transmitter includes electronic circuitry which scans the keys and auxiliary switches, and transmits an FM signal modulated by a serial digital pulse train identifying the transmitter keys which are depressed and the auxiliary switches which have been actuated. The receiver unit decodes the transmitted pulse train, eliminates erroneous data, and generates output signals to control the corresponding keys and auxiliary functions.

Abstract: An automatic rhythm performing apparatus comprises a voltage-controlled variable frequency clock generator, a plurality of tempo determining voltage signal sources, a selector for selectively coupling one of the tempo determining voltage signal sources to the clock generator, and an automatic rhythm generating circuit including a counter for counting clock pulses from the clock generator and generating a rhythm in response to the clock signal. The tempo of the rhythm produced by the rhythm generating circuit is dependent upon the magnitude of a tempo determining voltage coupled to the clock generator. A control circuit having a foot switch and a rhythm start switch may be provided to control the selector and counter. The counter is enabled to count the clock pulses by the operation of the rhythm start switch. The operation of the foot switch causes the counter to be disabled or causes the tempo determining voltage source coupled to the clock generator to be switched from one source to another.

Abstract: A carillon keyboard instrument is provided for playing bells and auxiliary bell tones, with a pedal provided for allowing the player to adjust the relative intensities of the major and minor tones of the bells. The instrument utilizes two sets of vibrator bars, a first set for generating major tones, and a second set for generating minor tones. By mixing the derived signals from corresponding major and minor vibrator bars, and adjusting the relative intensity of the minor signal strength, a new flexibility is provided to the instrument player for generating desired Flemish bell tones.

Abstract: An electronic music box circuit is provided which includes a pulse generator, a read only memory having address lines to be energized in a predetermined order by the output pulse signals from the pulse generator and memory cells arranged in accordance with a given melody, and a frequency-divider which divides the frequency of the output pulse signal from the pulse generator to produce a plurality of signals with different frequencies. In the read only memory, when one of the address lines is energized, a musical scale signal selection circuit and a signal level selection circuit are energized so that an output signal with a frequency selected from the output signals of the frequency divider is generated from the scale signal selection circuit while at the same time an output signal with a selected signal level is generated from the level selection circuit. The output signals from the scale signal and level signal selection circuits are supplied to a loudspeaker thereby to generate a predetermined sound.

Abstract: The specification discloses a musical tutoring device for teaching a wide variety of rhythms and tempos. The device includes a housing. A keyboard is mounted on the housing and includes an array of numerical switches, each corresponding to a different digit and selectively operable to enable the operator to input a musical tempo value, time signature value and a starting location. The keyboard further includes an array of musical note switches, each corresponding to a different musical note value and selectively operable to enable the operator to input a predetermined sequence of musical note values of a musical composition. Storage circuits are provided to store the tempo value, time signature value and musical note values. Circuitry is provided to produce a sequence of tones, the duration and spacing of the individual tones of the sequence corresponding to the stored musical note values. The rhythm and tempo of the composite tone sequence are dependent upon the stored tempo and note values.

Abstract: An electronic rhythm "break" pattern generator for use with a rhythm generator of the type used with electronic organs. The break pattern generator, when operative, interrupts the flow of the normal rhythm pattern and substitutes a special rhythm pattern for one cycle of the normal rhythm pattern. The typical pattern is of a type usually played by experienced musicians at the beginning, or end, of a musical composition and form "lead-in" and "lead-out" rhythm pattern portions. The system according to the present invention can also provide for an alternate rhythm pattern at any time not limited to the beginning or end of a composition.

Abstract: Musical notes are produced polyphonically in a tone synthesizer or like musical instrument by computing a master data set, transferring data set to buffer memories, and repetitively converting in real time contents of memories to notes. The master data set is created repetitively and independently of tone generation by computing a generalized Fourier algorithm using stored sets of generalized Fourier coefficients. Computations limit tones to audible frequencies, occur at intervals short compared to musical tone periods, and circuitry is included to provide time-varying modulations of the synthesized tonal structure. Synchronizing signals included in the buffer memories provide smooth transition between the master system logic clock and asynchronous tone conversion clocks. A time shared digital-to-analog converter transforms the buffer memory outputs to individual tone channels and provides attack, decay, sustain, release and other amplitude modulation effects.

Abstract: A digital type electronic musical instrument generates a tone signal consisting of a plurality of time-varying partial tone signals each by recursive calculation. A recursive calculator is of a simplified construction by arranging the amplitude term to be excluded from the recursive calculation and to be multiplied thereafter. A remarkable reduction in the memory units can be accomplished by arranging the pair of initial values for each partial tone function to be equal to each other by the introduction of a phase term into the periodic part of the partial tone function.

Abstract: A multiband speaker system means includes a high frequency section normally balanced with one or more lower freqency sections. A thermistor is serially associated only with the high frequency section whereby, for certain high power signal combinations, a lesser proportionate increase in output occurs in the high frequency section than the low frequency section. This not only makes possible a lower power rating, but also eliminates certain effects that are not musically desirable.

Abstract: Tone generation in a musical instrument is accomplished by repetitively computing a Fourier algorithm using stored sets of harmonic coefficients. An alterable voice is obtained by optically reading a data card, converting the data to a data format used by the tone generating circuitry, and storing the converted data to be employed as a set of harmonic coefficients. Harmonic coefficient data is encoded on the data card by imprinting columns of opaque areas. The length of each column is measured by sequentially scanning a linear array of light sources. Insertion of the data card in an enclosure automatically initializes the reading circuitry and removing the card causes each opaque data column to be measured in turn and the result converted to a harmonic component.

Abstract: In this electronic musical instrument, two separate tone generators of different type each produce a tone corresponding to an actuated key switch. Advantageously, one of the tone generators is of the Fourier synthesis type. In the other tone generator, a source waveshape having abundant harmonic components is processed by a tone color and volume control system which modifies the frequency spectrum and amplitude of the source waveshape in a time variant manner. The two generated tones are combined to produce the desired musical note.Actuation of each key switch produces, in an assigned time slot, frequency information corresponding to the selected note, and designating the phase angle between successive sample points to be read from a waveshape memory. In the Fourier synthesis type generator, plural waveshape memories store harmonically related sinusoids, all of which are accessed simultaneously and weighted by harmonic coefficients to produce the first tone.