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

Abstract: 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 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: An electronic musical instrument is of a type wherein a key depression brings forth the generation of a key code identifying the depressed key in a digital representation, and the key code designates the tone to be produced. Based on the single key code of the depressed key, there are produced plural key codes indicating plural tones which are in predetermined musical interval relation with the depressed key to constitude a chord. The original key code and the produced key codes are utilized one after another successively to perform an automatic arpeggio.

Abstract: An electronic musical instrument having an automatic performance device includes a memory storing in addition to automatic performance data, envelope control data for controlling envelopes of automatic performance tones to be generated. The envelope control data has two logical values and is used for controlling the envelope of the tone at the decaying portion. The value "0" designates a gradual decay and the value "1" designates a quick decay. The automatic performance tones are respectively imparted with either of the gradual and the quick decay shapes suitable for the time intervals between the generated tones in the designated automatic performance pattern.

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

Abstract: Key switches are connected in a matrix fashion between row lines making block lines for octaves and column lines making note lines for notes. The note lines are connected to a note detection circuit which converts the note line outputs of the actuated switches into key codes in a time shared fashion and to a chord detection circuit which includes a chord type detecting logic and a shift register connected thereto and storing the note line outputs in its respective stages. During a chord detecting period, the note detection circuit is loaded with signals "1" as if all the key switches were actuated and delivers key codes of all notes one after another, whereas the shift register is circulatingly shifted synchronously with the note code change. When the logic detects an establishment of a chord, the note code of that moment is extracted to be a code identifying the root note of the chord. The root note code is then processed for automatic bass and chord performance.

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

Abstract: An electronic musical instrument is provided with an upper, a lower and a pedal keyboards and musical tone generating circuits dependently corresponding to respective keyboards and, in addition thereto, an auxiliary musical tone generating circuit which is independent of the keyboards and can be selectively coupled with a particular keyboard according to the designation by a keyboard selection switch. This auxiliary musical tone generating circuit produces tone signals having a particular tone color. Key codes for a selected one of the keyboards among key codes supplied by a channel assignment circuit are latched separately in the auxiliary circuit, and musical tones corresponding to the latched key codes are produced in this particular tone color.

Abstract: An electronic musical instrument of a key code processing type includes a single tone generating section for producing a solo performance effect without providing a solo performance keyboard. This single tone generating section comprises a single data selection circuit which selects the highest (or lowest) note from among notes of depressed keys for producing a single musical tone. The single data selection circuit includes first and second memories and a comparison circuit. An input key code A is compared with a key code X stored in the second memory and the input key code A is stored in the first memory if the value of the input key code A is greater than the value of the key code X. When one cycle of the above described comparison has been completed, the data stored in the second memory is rewritten with the data of the first memory. The key code for the highest note is now stored in the second memory to designate a tone signal to be produced for a solo performance.

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

Abstract: A keyboard electronic musical instrument comprises a note information processing device capable of processing note information required for automatic arpeggio and automatic bass performances. This note information processing device includes a generation circuit for generating a plurality of note information representing a plurality of notes to be sounded in relation to the key depression, a selection circuit for sequentially selecting a note information designating a note to be sounded from among the plurality of note information from the generation circuit in accordance with a predetermined priority order; an output circuit for delivering out the note information selected by the selection circuit, the selection at each sequence being conducted dependent on the selection at the preceding sequence.

Abstract: A tone production assignment circuit produces control information representing assigned key code, key-on etc. Such information has a large number of bits with respect to each channel. A multiplexing circuit has output lines the number of which is smaller than the bit number of the information and divides the information with a plurality of time slots with respect to one channel. The multiplexing circuit is controlled by a signal from a timing signal generation circuit. The multiplexing circuit is capable of rearranging information for transmitting information required for the respective individual channels and also capable of inserting a timing data in an available time slot. A multiple data analysis circuit decodes the information provided by the multiplexing circuit. Tone generators are provided for the respective channels and each one of them functions to latch only corresponding information among the decoded information by a latch circuit.

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: In an electronic musical instrument, numerical values corresponding to respective notes are generated on a time-shared basis, the generated numerical values are cumulatively added for each note in synchronism with a predetermined time slot and carry signals coming out as results of the accumulations of the respective numerical values respectively constitute note frequency signals. By simplifying a tone source circuit in this manner and by selecting generated frequency signals in accordance with depression of keys, the number of conductors connecting a keyboard circuit with the tone source circuit can be reduced.

Abstract: An envelope generator is provided with a count circuit the count value of which is varied through addition or subtraction or combination thereof, and a conversion circuit which operates to convert the count value into amplitude data, so as to generate an envelope having a shape corresponding to variations with time of the count value. According to one aspect of the invention, the count circuit is a circuit which carries out computation for exponentially varying the count value through polygonal line approximation, so as to form an envelope of exponential characteristic. According to another aspect of the invention, the conversion circuit is a memory which has stored amplitude data corresponding to count values in advance so as to convert count values in the last linear region of the envelope obtained by the polygonal line approximation into amplitude data in exponential relation and to convert count values contained in the remaining polygonal line regions into amplitude data in linear relation.

Abstract: An electronic musical instrument comprises an upper keyboard channel, a lower keyboard channel and a pedal keyboard channel. The lower keyboard channel includes a tone gate which is actuated by a chord rhythm pattern pulse generated by an automatic rhythm generator to gate the lower keyboard tones. The pedal keyboard channel includes a root/subordinate tone generator which provide a root tone designated by the depressed pedal key and subordinate tones related to the root tone with predetermined musical intervals, and a tone keyer which is actuated by a bass rhythm pattern pulse generated by the automatic rhythm generator to gate the bass tones.

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: 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: An envelope generator comprises a counting circuit and counting control means capable of controlling a counting mode of the counting circuit, i.e., operation and non-operation of the counting circuit, counting speed, addition and subtraction etc., in accordance with an envelope shape to be obtained. There are various predetermined counting modes corresponding to different envelope shapes and the envelope generator includes selection means for causing the counting control means to select a desired one of the counting modes.