Abstract: The present invention provides a system in an electronic musical instrument for measuring the setting of a variable resistor for controlling tempo, displaying the tempo to which the setting corresponds, and controlling the tempo so that notes are sounded in accordance with the setting measured and displayed. The tempo control comprises a tempo potentiometer that is self-calibrating by means of a microprocessor which automatically measures the resistance of both the current setting of the tempo potentiometer and the maximum setting of the potentiometer so as to maintain the desired correspondence between the mechanical position of the tempo potentiometer and the tempo selected. A non-linear relationship is introduced between the mechanical position of the tempo potentiometer and the tempo selected in order to maintain a desirable correspondence between the mechanical position of the tempo potentiometer and the tempo selected.

Abstract: A central processor for an electronic organ in the form of a single, forty pin integrated circuit chip employing multiplexed technology and trinary and tri-level inputs to obtain maximum usage from each pin. The solo manual keys, chord keys, rhythm pattern switches and other control functions are multiplexed externally of the chip, fed into the chip as a time division multiplexed four bit byte over four pins, and demultiplexed internally of the chip. The solo manual information is multiplexed internally of the chip to form a single serial data stream, is combined with solo fill note data generated within the chip and then brought out over a single pin for external demultiplexing. The twelve tones of a musical octave are brought into the chip over twelve pins together with various static control signals, are decoded by tri-level decoders internally of the chip, and then utilized to generate the tones of the chords, also internally of the chip.

Abstract: Predetermined keys in a keyboard are used as reading keys for specifying the reading of note codes memorized in a memory section under the control of a function changing switch. Sounds corresponding to the note codes memorized in the memory section are delivered from a loudspeaker with a plurality of different volume levels set in the order of arrangement of the keys set as the reading specification keys.

Abstract: An electronic organ, particularly of the institutional type employing classical voicing, having Swell and Great manuals as well as a full pedalboard wherein the manuals and pedalboard are multiplexed simultaneously to produce a plurality of synchronized serial data streams. Intermanual coupling is accomplished by connecting the data stream from one manual to the footage generation circuit of another manual, and footages are generated for each manual by utilizing tapped shift registers introducing controlled amounts of delay of the keyboard data before demultiplexing thereof. There is a bank of demultiplexer-keyers for each voice, such as flutes, principals, complex and percussion, which receive the serial data streams from one or more of the footage generators. The demultiplexer-keyers are supplied with tones and function to demultiplex the serial data streams and provide tones to the voicing circuitry selected in accordance with the keydown pulses in the serial data streams.

Abstract: A guitar synthesizer comprises a guitar portion and a synthesizer portion which are electrically connected to each other. The guitar portion includes strings stretched between a nut and a bridge and pickup means for detecting a string vibration for providing a guitar sound signal. The guitar sound signal is applied to the synthesizer portion. The synthesizer portion comprises a voltage controlled variable bandpass filter exhibiting a passband characteristic variable in at least two frequency regions of the guitar sound signal as a function of a control voltage. A frequency/voltage converter provides a control voltage representing the frequency of the output of the filter, to the variable bandpass filter, whereby the passband characteristic thereof is made adaptively and dominantly responsive to the frequency of the fundamental wave component included in the guitar sound signal and the fundamental wave component is extracted with accuracy from the guitar sound signal.

Abstract: An automatic rhythm performance device is of a type in which an intro performance which is in a rhythm pattern different from a rhythm pattern of main performance to be performed amidst music progression is automatically provided at the start of an automatic rhythm performance. To provide the intro performance, this device has a memory for storing special rhythm patterns in addition to regular rhythm patterns for main performance. At the start of the automatic rhythm performance, this memory is made operable for a predetermined time period so that the intro performance is executed on the basis of intro pattern pulses read out from the memory. The intro performance is inhibited when "synchro start mode" which starts the automatic rhythm performance in synchronism with key depression is being selected.

Abstract: An electronic musical instrument comprises a musical tone production circuit responsive to a depressed key among a plurality of keys, and a control circuit for controlling tone production manner which includes a plurality of manually operated members mounted on a control panel for setting parameters that determine the tone production manner. There is also provided presetting means for presetting some of the parameters. At an initial state after the instrument is powered from a power source, the preset parameters dominate the corresponding ones of the manually set parameters, while the preset parameters can be replaced by the manually set parameters at a choice of a player after powering.

Abstract: This electronic musical instrument with automatic accompaniment system comprises means for dividing each note by time division timing, means for extracting a timing equivalent to the order indicated by pattern signals from the timings corresponding to the predetermined note, and means for producing a musical tone of note corresponding to the extracted timing. The automatic accompaniment system may be applied for automatic arpeggio performance.

Abstract: An electronic musical instrument equipped with multiple musical tone signal generating channels, with an automatic play system which controls the tone generation of the musical tone signal generating channels on the basis of the automatic play data recorded in a memory so as to successively and automatically generate musical tones. The instrument also has a manual play system which controls the tone generation of the musical tone signal generating channels by the keyboard and other performance controls so as to generate musical tones by control of the tone generation of the multiple musical tone signal generating channels by the joint use of the automatic play system and the manual play system.

Abstract: A sequence of timing signals is generated having a time spacing corresponding to the average spacing between successive actuations of a control switch. The system automatically starts a new calculation if the control switch is actuated at least two times with a time spacing less than some prespecified threshold time. The data input process is self-terminated when a time interval equal to the threshold time expires after an actuation of the control switch. The generated sequence of timing signals can be used as the metronome clock for an automatic rhythm generator.

Abstract: A keyboard operated electronic musical instrument with polyphonic portamento and glissando effects in which each key controls one of a number of tone generators through a table of frequency numbers. The frequency transitions are achieved by subtracting the frequency number of a new note from the frequency number controlling the current frequency of an assigned tone generator. A predetermined fraction of the difference is stored in increment registers and added successively to the frequency numbers of the current notes until these numbers are equal to the frequency number of the new note. The addition rate, which determines the frequency transition time, is adjustable by means of a variable frequency time clock. The assignment of the tone generators to the actuated keyswitches is accomplished in a manner which prevents objectionable frequency cross-over transitions even when the number of notes in successive chords is changed.

Abstract: The tone production system for an electronic musical instrument comprises depressed key detection means for outputting pulses at a timing corresponding to a key depressed by time division timings assigned to each note, a shift register for shifting successively said pulses outputted from said depressed key detecting means in synchronism with said time division timing, key data forming means for taking out each output pulse of predetermined plural stages of said shift register in accordance with a desired type of chord, musical tone production means for producing each of plural musical tone signals of notes corresponding to pulse generation timings in accordance with each pulse taken out by said key data forming means.

Abstract: The invention relates to a device for the acoustic indication of the beats of a musical time in which the tempo at which the beats are reproduced is adjustable. According to the invention means are provided for varying the musical properties of the separate beats, e.g. the reproducing period, the volume and the pitch, said varying means being provided with N switch elements each having at least three switch settings, and a scanning element for the cyclic consecutive scanning of the N switch elements, wherein a tone is generated in a first channel during the scan period of each of the switch elements in the second switch setting of the switch element, while a tone is generated in a second channel in the third switch setting of the switch element and no tone is generated in the first switch setting of the switch element in either channel, both channels being common to the N switch elements.

Abstract: In an electronic musical instrument of a digital processing type, an operation of a key causes the generation of a digital value corresponding to the operated key and a tone having a frequency determined by that digital value is produced. The instrument comprises a key assigner which assigns the operated keys from among a large number of keys to a small number of channels, which small number is a number of maximum available tones to be produced simultaneously. The instrument further comprises a modifying value generator for generating modifying values for the respective channels, the value being a first value upon key operation and subsequently varying to a second value to provide an attack pitch fluctuation effect. The key assigner and the modifying value generator are of a time division multiplexing type with the channels being defined by the corresponding time slots.

Abstract: This electronic musical instrument comprises means for selecting one of a plurality of performance modes and musical tone production means having tone production channels less than the number of keys. Tones are produced through said channels based on the time division multiplex key data which are set according to the depressed status of all key in the different manner according to the selected performance mode of the mode selecting means.

Abstract: An electronic organ, particularly of the institutional type employing classical voicing, having Swell and Great manuals as well as a full pedalboard wherein the manuals and pedalboard are multiplexed simultaneously to produce a plurality of synchronized serial data streams. Intermanual coupling is accomplished by connecting the data stream from one manual to the footage generation cirlcuit of another manual, and footages are generated for each manual by utilizing tapped shift registers introducing controlled amounts of delay of the keyboard data before demultiplexing thereof. There is a bank of demultiplexer-keyers for each voice, such as flutes, principals, complex and percussion, which receive the serial data streams from one or more of the footage generators. The demultiplexer-keyers are supplied with tones and function to demultiplex the serial data streams and provide to the voicing circuitry tones selected in accordance with the keydown pulses in the serial data streams.

Abstract: An automatic accompaniment circuit which is provided with a code detector for scanning key switches to detect the code of a depressed one of the key switches, a latch circuit for latching the output signal of the code detector by a bar clock pulse which is produced for each bar, a comparator for comparing the output signals of the code detector and the latch circuit to yield a coincidence signal, and control means for counting the coincidence signal from the comparator by a desired number of bars using the bar clock pulses and then providing a command signal for changing the pattern of an automatic accompaniment.

Abstract: An electronic music book for simplifying the storage and retrieval of musical scores in which a control panel operates electronic memories to locate a song in the memory for a musician's reading thereof. Optional modules may be added to the memory to expand the lilbrary of songs stored by the book. A variety of additional features may be included in the music book, such as audio playback of a selected song, tempo and rhythm control, and a temporary memory for musical works entered through a musical keyboard in the control panel. The book is adapted to be attached to a music stand and may be battery operated for portable use or permanently connected to a source of A.C. voltage.

Abstract: The electronic musical instrument is provided with a tone production means having tone production channels less than the total number of keys, a performance mode change detecting means, and a means for controlling tone production assignment of the tone production channels.The tone production assignment is controlled by depressed keys to one of the detecting means to produce a tone from one of the channel groups grouped according to the output of the detecting means. The selected tone production channel corresponds to the key group which the depressed keys belong to.

Abstract: For the purpose of sequentially varying a tone pitch of a generated musical tone, a variation information generator is provided which is operable by a performer to generate a variation information designating an arvitrary variation rate of the tone pitch. An operation circuit is provided for producing a modified frequency information in response to the variation information and a frequency information representing a tone pitch regarding a depressed key. The modified frequency information is supplied to a musical tone signal generator and the output thereof is applied to a sound system for generating the musical tone, thereby obtaining a musical effect similar to glissando or portamento and having an arbitrary variation rate.

Abstract: A tempo control device for automatic performance according to this invention is of a type wherein a tempo of automatic performance is caused to automatically follow that of manual performance as the latter changes during performance. When difference in tempo between manual and automatic performance falls within a predetermined range, this automatic follow-up control is performed by measuring the manual performance tempo with accuracy and by controlling the frequency of tempo clock pulses in the automatic performance on the basis of the value thus measured. The predetermined range may be one fixed range for all notes of various note-lengths, or alternatively, different ranges may be employed in accordance with the length of notes.

Abstract: An electronic musical instrument comprises a keyboard, a tone signal forming circuit to produce musical tone signals corresponding to keys being depressed on the keyboard, a memory to store musical performance data, a keyboard display device to visually instruct a pupil or trainee as to which keys are to be depressed on the keyboard in accordance with the performance data read out of the memory so that the pupil or trainee may effect a musical performance on the keyboard while following key indications, and an automatic musical performance device to effect an automatic musical performance of different type from the musical performance effected on the keyboard. The pupil or trainee may selectively effect the musical performance on the keyboard with or as the accompaniment by or for the automatic musical performance.

Abstract: An automatic rhythm accompaniment system comprises memory units storing a plurality of rhythm patterns and a designating switch for selecting a desired rhythm pattern. A memory unit is further contained in the system for previously storing chord progress data and further storing control data to fill in an ad-lib rhythm. Therefore, the rhythm accompaniment system may perform the ad-lib rhythm in place of the rhythm pattern by the switch designation for each measure. Additionally, the accompaniment based on the chord progress data may also be performed automatically.

Abstract: In an automatic performing apparatus, an amount of change in a motion of a moving element provided in a baton is detected, and the detected change amount is converted into an electrical signal. A tempo clock signal generator provided in the apparatus is driven by the electrical signal to produce a tempo clock signal for reading out musical data preset in a memory. A volume level of a musical tone is set by a control section on the basis of the data of a peak level of the change amount in the motion of the baton. The tone data stored in the memory is read out on the basis of the tempo clock and is automatically sounded as a musical sound, at the set volume level.

Abstract: An electronic musical instrument capable of providing automatic bass and chord accompaniments, either in accordance with a program prepared by the player or in immediate response to the depressing of a minimum number of keys on lower and pedal keyboards. The programmed accompaniments proceed sequentially (in steps) with successive measures of accompaniment data being read from a memory. By making some of these measures blank in introducing the accompaniment data into the memory, therefore, the player can play desired bass and chord accompaniments by direct key depression during the blank measures. In an alternative embodiment the production of the programmed accompaniments is automatically inhibited during the production of key-responsive accompaniments, thereby enabling the player to override the programmed accompaniments at any time.

Abstract: An asynchronous interface between a data input system (computer) and the keyboard multiplexer of an electronic musical instrument (digital organ) includes a pair of RAMs. The interface synthesizes the multiplexed keyboard data stream of the digital organ by swapping read and write operations between the two RAMs. Predetermined key data (WRITE DATA) provided by the computer is written into one RAM during a WRITE interval while key data (READ DATA) previously written into the other RAM is sequentially read out of the latter RAM. The WRITE DATA designates those keys on the organ keyboard which are to be simulated as being active. The read and write operations are alternately applied to each RAM. If the READ DATA matches the key code assigned to a key on the keyboard, the appropriate note is sounded by the organ. The two RAMs can actually be two segregated portions of a single memory.

Abstract: An electronic musical instrument in which rhythms are each subjected to digital processing and provided uniformly with out variations in volume and tone quality and respective envelope waveshapes are given different periods of attack and decay which are obtained with the same system by calculating attack and decay coefficient for the respective rhythms on a time divided bases.

Abstract: A polyphonic, keyboard-type electronic musical instrument capable of automatic production, in response to key depressions on upper and lower keyboards, of "fill notes" which bear the same note names as the depressed lower keys but which, preferably, fall within an octave below the lowest pressed upper key at every moment. The instrument is of the type wherein each depressed key is coded into key data in accordance with a binary "key code" composed of a note code and an octave code. The note code identifies the note name of each key, whereas the octave code identifies the octave to which the key belongs. Upon depression of a key on each of the upper and lower keyboards, the note-coded data derived from the key date representative of the depressed lower key are combined with the octave-coded data derived from the key data representative of the depressed upper key if the note name of the depressed lower key is below that of the depressed upper key.

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

Abstract: An electronic musical instrument is of a type in which bass/chord performance can be automatically performed without depression of the keys on the keyboard. This electronic musical instrument has a chord constituent note data producing circuit which stores several kinds of chord progression patterns each of which consists of a series of plural chord data aligned in sequence. The chord progression pattern to be played is selected by the chord progression designation switch. The chord note data producing circuit has a memory for storing a root note of each chord as the chord data, and circuit for producing subordinate note data based on the chord data and tonality for the chord. Data for bass tone is obtained by a root note detection circuit for producing a root note data, a pattern producing circuit for producing bass pattern data, and an adder for adding the root note data and the bass pattern data.

Abstract: An automatic performance device comprises a pattern memory for storing a plurality of performance patterns and a sequence memory for storing a pattern progression. The pattern progression is programable and is written in the sequence memory. The performance patterns are selected one by one from the pattern memory according to the pattern progression. Each selected performance pattern is read out according to a tempo pulse. An automatic performance is carried out on the basis of the read-out performance pattern.

Abstract: A musical door chime which includes a repertoire of musical tunes one of which is played when a door pushbutton, preferably the front door pushbutton, is actuated. The musical tune which is played may be selected by means of a keyboard connected to a microprocessor. Digitally encoded representations of the notes of each musical tune are stored in a memory. Each digitally encoded musical note is read from memory by the microprocessor and converted by the microprocessor into a squarewave having the frequency and the duration of the note. The microprocessor is connected to a note strike and decay circuit which is preferably connected in series with an active audio filter circuit for translating the squarewave into a sinusoidal output for energizing a loudspeaker so that relatively high quality audible tones are heard when the musical tune is played.

Abstract: A sequence generator system is disclosed for use in an electronic musical instrument wherein scanning circuits scan the instrument and produce a serial data stream corresponding to notes played on the instrument. The sequence generator system comprises sequence generating circuits responsive to the serial data stream for generating a further, predetermined data sequence and data steering circuits for receiving the serial data stream and for normally steering said serial data stream to a data output. Actuation of the system causes the data steering circuits to substitute the predetermined data sequence produced by the sequence generating circuits for the serial data stream at the data output.

Abstract: An electronic organ, particularly of the institutional type employing classical voicing, having Swell and Great manuals as well as a full pedalboard wherein the manuals and pedalboard are multiplexed simultaneously to produce a plurality of synchronized serial data streams. Intermanual coupling is accomplished by connecting the data stream from one manual to the footage generation circuit of another manual, and footages are generated for each manual by utilizing tapped shift registers introducing controlled amounts of delay of the keyboard data before demultiplexing thereof. There is a bank of multiplexers for each voice, such as flutes, principals, complex and percussion, which receive the serial data streams from one or more of the footage generators. The demultiplexer-keyers are supplied with tones and function to demultiplex the serial data streams and provide tones selected in accordance with the keydown pulses in the serial data streams to the voicing circuitry.

Abstract: An electronic musical instrument is of a key assigner type including a key coder and a channel processor, and is equipped with an automatic bass/chord performance faculty. The key coder includes a root note memory and a chord type memory, whereas the channel processor includes a key code memory and a key-on memory. The instrument is provided with a chord note memory function rendering switch and a bass note memory function rendering switch. When the chord note memory function rendering switch is turned on, the key-on memory is not cleared after release of the keys for conducting a automatic performance of chord tones. When the bass note memory function rendering switch is turned on, the root note memory and the chord type memory are not cleared after release of the keys for conducting an automatic performance of bass tones.Thus a bass-note memorized automatic accompaniment performance and a chord-note memorized automatic accompaniment performance are independently selectable.

Abstract: An automatic rhythm-pattern accompaniment equipment is disclosed that can automatically stop the full-in rhythm sound superposed on or replacing the accompaniment rhythm sound in synchronization with the beat number determination signal. According to a feature of this invention, the automatic rhythm accompaniment equipment comprises a fill-in circuit synchronized with basic rhythm pattern and fill-in beat number determination circuit, a fill-in rhythm-pattern designation circuit and a fill-in rhythm-pattern generator. Therefore, the stop of the fill-in rhythm is carried out automatically by the electronic circuit in synchronization with the beat number determination signal, although the insertion of it is manually done by the music player. If necessary, the insertion of the fill-in rhythm can be synchronized with the beat number determination signal.

Abstract: In an electronic musical instrument apparatus is provided for generating musical sounds having a fundamental frequency which tracks the fundamental frequency of a time varying external control signal. A matched filter is used to generate frequency control signals which are determined by a closeness criterion between the external control signal and an internally generated test signal. Provision is made for offsetting the generated musical sounds for a preselected musical interval from the fundamental frequency of the external control signal.

Abstract: An automatic accompaniment apparatus which has an auto-bass circuit and an auto-arpeggio circuit. In the auto-bass circuit, note information concerning one kind of code is stored in a memory (ROM), and a code signal is detected from depressed key information in a code detector, and in a note converter a note signal from the memory is converted by the code signal to a note signal corresponding to the kind of code, whereby note signals of various kinds of codes are generated. In the auto-arpeggio circuit, note information concerning one kind of code is stored in a memory (ROM), and a code signal is detected from depressed key information in a code detector, and in a note converter a note signal from the memory is converted by the code signal to a note signal corresponding to the kind of code. The note signal is added with a root signal from the code detector, and by the added output, a scale signal is selectively obtained, which scale signal is frequency divided by an octave signal from the memory.

Abstract: An electronic musical instrument by which a performer can provide a musical accompaniment in different musical harmonies by playing on a standard keyboard. The performer adjusts a tempo clock in order to determine the period of the rhythmic beat of the accompaniment. The instrument enables the performer to change to a different harmony at the end of a beat (e.g., by changing his hand position on the keyboard) without interrupting the continuity of the accompaniment and to hear much of the subsequent beat in the changed harmony even if his hand does not complete the change to the new harmony position until a portion of the subsequent beat has elapsed.

Abstract: An electronic organ includes a plurality of buffers for receiving solo keyswitch status information, accompaniment keyswitch status without octave information, and depressed keyswitch status from an arpeggio keyboard. A scan circuit and a microprocessor gate the buffers into an input memory which retains an image of the solo, accompaniment, and arpeggio keyboards. A control program, stored in ROM, is responsive to the input memory, shared registers, and harmony switches actuable in several modes, to produce one or plural harmony notes in either open or closed harmony, and to assign different note names to the actuated keyswitches on the arpeggio keyboard. The resulting harmony and arpeggio notes are stored in an output memory and are transferred to a transistor matrix which activates solo keyers to produce harmony and arpeggio notes with solo voicing. A rhythmic harmony modulator is actuable to modulate the harmony notes in a rhythmic pattern of individual and delayed beats.

Abstract: Music playing apparatus for playing selected musical notes in accordance with a selected rhythm pattern. A rhythm pattern is selected having a multiplicity of intervals. The rhythm pattern is repetitively reproducible and musical notes played at any interval within the rhythm pattern may be selectively played as either an unaccented note or as an accented note. Selected musical notes are played at each interval within the rhythm pattern and the pitch of a selected note is determined. The pitch of a selected note is within a predetermined range of octaves in the chromatic scale and this range of octaves may be selectively extended. A tone generator generates audible musical tones in accordance with the established rhythm pattern, the selected musical notes, and the octave band within which the selected musical notes are found.

Abstract: An electronic apparatus for teaching and reading music comprises: a tone generator connected, via logic control gates, to a system for reproducing the sound; a keyboard for selecting the notes of the scale to be generated each key of which may be compared to a symbol of the corresponding note which is located on or adjacent to that key; and at least one set of control buttons for selecting the time duration of each scale or rest note, with each control button designated by a symbol of the time duration of the scale or rest note. Each key or button also has a corresponding electronic visual display (LED) to indicate its selection. A multichannel, pluriaddress, memory device is provided for WRITING-in and READING-out musical data. The apparatus also includes a mode selection switch with which to select operation of the device for reading or writing. A variable frequency generator sets the timing of the music to be played.

Abstract: An electronic musical instrument is of a type in which chord constituent tones are automatically produced at timings determined by the rhythm to be played and according to random selection of notes. A rhythm pattern pulse generator generates a rhythm pattern pulse representing the timings of tones to be sounded according to the selection of the rhythm. A constituent degree data generator generates, at the timings of the rhythm pattern pulse, degree data signals representing degrees of chord constituent notes, wherein the degrees are aligned in a random order. Tones are produced of the notes designated by the degrees and the root note of the chord. Thus an automatic performance is realized with the notes constituting a chord but appearing in a random order.

Abstract: In an electronic musical instrument which is arranged to produce musical tones belonging to the selected one of many different types of musical instruments and having a number of player-operable selection keys respectively corresponding to the number of types of musical instrument sounds desired, the improvement wherein means is provided for generating a sample tone belonging to that type of musical instrument specified by one of the above-mentioned selection keys at a prescribed pitch and period simply by depressing only once a particular selection key, without taking the trouble of successively depressing individual performance keys, thereby facilitating the selection of a desired type of musical instrument by the player.

Abstract: A dynamic one finger chording system with memory is connected in parallel relationship to the d.c. keying lines connecting a select number of keys of the manual to a standard keyer circuit of an electronic organ. The one finger chording system scans each keying line until a line with a d.c. level voltage signal corresponding to a manually depressed key is detected. An identification of the detected line is used as the address to a read only memory. In response to the address, the read only memory provides a preselected d.c. level output signal which through appropriate output circuits drives respective keying lines. Thus one keying line has a d.c. level signal due to the manual depression of a key and a predetermined number of keying lines have a d.c. level signal due to the output signal from the one finger chording read only memory. The same keyer circuit that is used during normal playing now provides a chord output signal.

Abstract: An electronic musical instrument includes twelve multiplexed wave data generators each of which corresponds to one of twelve musical notes in an octave and produces a multiplexed wave data signal which has a basic pulse frequency decisive of a note and has data indicating states of octavely related plural waves for the same note in a time-division-multiplexed manner. A note selection circuit selects a multiplexed wave data signal for the note designated by the depressed key. The selected wave data signal is converted by a shift register to parallel wave data signals, which are latched by a latch circuit. Selection of the octave is made by the latching time of the latch circuit determining the positions of the bits in the shift register to be latched. Rewriting of latched data in the latch circuit is effected each time the value of the data signal having the highest frequency among the wave data signals varies.

Abstract: A chord recognition system for an electronic musical instrument, namely an electronic organ. A shift register receives data information from the keying lines of selected playing keys. The pattern of the received data is compared against selected normalized chord patterns in a program logic array to determine if the note input sequence is in a known musical relationship such as major, minor, minor sixth, seventh or others. A chord logic circuit receives the information from the programmed logic circuit and further reduces the information to output signals indicating a major, minor, or seventh chord and a pattern found signal. If no chord pattern is detected in the input data sequence, the register shifts the data on its first input line to its last input line and all other data is transferred downward accordingly. A counter sequences at each shift of the data input information. The shifted data is now compared in the programmed logic array as described above.

Abstract: An electronic rhythm generator which comprises a large read only memory having a plurality of rhythm patterns and rhythm break patterns programmed therein, player operated selector switches for selecting a rhythm pattern and a break pattern, scanning circuitry for sequentially addressing the memory to read out the stored rhythm pattern, and, when the break circuitry is activated, reading out the break pattern in place of or in addition to the rhythm pattern. The rhythm generator is contained on a single monolithic integrated circuit chip with the pattern selection being accomplished by an external multiplexer driven by an internally generated scan word. The break activation circuitry automatically corrects for improper matching of a rhythmically incompatible rhythm pattern and break pattern by either ignoring the break command or substituting a compatible break pattern in place of the selected break pattern.

Abstract: A display device for an automatic rhythm performance apparatus comprises a common display unit which selectively displays tempo and rhythm advancement of the automatic rhythm performance. For this purpose, the device has a selector for selecting the display contents so that the display of tempo is performed by numerical value before the rhythm starts, and the display of the rhythm advancement is performed by the number of measures, the number of beats and a demarcating mark between them after the rhythm starts.

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.