JPS599913B2 - automatic accompaniment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an automatic accompaniment device that performs bass accompaniment in accordance with a chord (chord) performance.

The automatic accompaniment device detects the chord name formed by the pressed key, temporarily stores information on this chord name, and generates a base note corresponding to the root note and subordinate note of the chord based on the stored information. I try to do that.

By the way, conventional devices require the same number of hold circuits as the number of detectable chord names to temporarily hold chord names, and also require a select circuit to select the base tone signal corresponding to the root note and subordinate note. Since circuits must be provided separately for each code name, a large number of hold circuits and select circuits must be used. This invention aims to reduce the number of the hold circuits and select circuits to a small number, thereby promoting miniaturization of the entire device and use of ICs. It was originally designed to obtain the desired bass sound.

In other words, the chord name detection information is converted into binary information (binary code) representing each note name of the root note and subordinate note (notes that have a certain pitch with respect to the root note and make up the chord together with the root note). , respectively, and generates a bass sound based on this binary information.
Therefore, there is no need to provide a separate hold circuit for each chord name, and since the chord name (or note name of the root subordinate note) is identified by the content of the binary information, it corresponds to one series of binary information. It is only necessary to provide a hold circuit with a The invention will now be described in detail with reference to the embodiments of the accompanying drawings. In the embodiment shown in FIG. 1, an automatic accompaniment method ( By pressing one key with the note name corresponding to the root note of the chord, the bass accompaniment corresponding to the chord name can be automatically played. We have shown a configuration that can selectively adopt an automatic accompaniment method (temporarily referred to as the 1' key press method) in which the accompaniment method (temporarily referred to as the 1' key press method) can also automatically proceed.

The keyboard circuit 40 generates a signal in response to the pressing of each key on the musical instrument keyboard, and the key switch output line for each key corresponds to the same note name on the 12-tone scale (
C to B), and 12 output lines corresponding to each note name of the 12-tone scale are derived from the same circuit 40. Normally, self-dynamic accompaniment is performed by pressing multiple keys, and in this case, the output of the keyboard circuit 40 passes through a self-holding circuit 50 and is sent to the chord name detection circuit 10.
and one tone selection circuit 30 in parallel.

The self-holding circuit 50 operates only when the one-key pressing method command signal 0F is applied, and self-holding the pressed key tone name signal from the keyboard circuit 40. This self-holding is released the next time another key is pressed. The chord name detection circuit 10 is a circuit that detects chord names formed by a plurality of keys pressed on the keyboard. It is configured to detect three types of chords: (a minor triad) and a seventh (a chord having an interval of a minor seventh).

The chord name is the note name of the 1st root note, 2nd note, whether it includes a minor 7th note, and 3rd major or minor (whether it includes a major 3rd note or a minor 3rd note). ), the chord name detection circuit 10 identifies whether the chord is a perfect fifth interval or a minor seventh interval and selects its root note. At the same time, it is detected whether or not a major third or minor third interval tone is included. An example of the configuration of the chord name detection circuit 10 is shown in the block diagram of the circuit 10 in FIG.

Here, the minor seventh, perfect fifth discrimination, root note selection circuit 11 is as follows:
A chord that includes a minor seventh interval or a normal perfect fifth
It identifies whether the chord is a degree interval chord, generates a minor seventh interval detection signal 7V or a perfect fifth interval detection signal 5, which is the identification result, and also produces a pitch name C corresponding to the root note of the identified chord. -B produces a root selection signal on the output line. Therefore, for example, when comparing chord C major and chord C seventh, the root note selection signal is generated on the output line of the same C note name, but the pitch detection signal 7V', 5 is generated separately. The J root note selection circuit 11 selects each note name C of the 12-tone scale.
- Each minor seventh interval chord when B is the root note,
It consists of a logic circuit that executes a logical formula for identifying and detecting a perfect fifth interval chord, and inputs a pressed key note name signal from the keyboard circuit 40 in response to a pressed key, and calculates the logic satisfied by this input. A root note selection signal is generated on the output line of the root note name of the chord corresponding to the expression, and when the satisfied logical expression is for a minor seventh interval chord, an interval detection signal 7I
' produces an interval detection signal 5 if it is of a perfect fifth interval chord. The logical formula for detecting a perfect fifth interval chord is , and the logical formula for detecting a minor seventh interval chord is , and these logical formulas are executed by constructing an AND circuit. .

Here, K is the root, K2 is the major second, K4 is the perfect fourth,
K5 is a perfect 5th, K6 is a major 6th, and K7XF is a pressed key pitch name signal input from the keyboard circuit 40 corresponding to a minor 7th pitch. The pitch name of each pitch K2 to K7 is uniquely determined. Furthermore, K2
・K4 and K6 mean that the keys of these pitches are not pressed. The AND circuits based on the logical formulas (1) and (2) are constructed separately, with each of the 12 note names C-B as the root note K1. When a logical formula of a certain AND circuit is satisfied, the note name C-B corresponding to the root K, which satisfies the logical formula.
A signal is generated on the output line of , which is added to the OR circuit group 14 as a root selection signal, and the logical formula is expressed as (1).
The pitch detection signal 5, depending on whether it is the formula or the formula (2),
75 is output. No matter which note name of the 12-tone scale C-B is taken as the root note, if the above equations (1) and (2) are not satisfied, all output lines of the root note selection circuit 11 become signal 0, and the NOR circuit NOR This is detected and a code name undetectable signal NC is generated.

When the chord name detection undetectable signal NC is applied from the NOR circuit NOR, the single note selection circuit 30 selects a single note name from among the plurality of keys pressed on the keyboard based on the output from the keyboard circuit 40. , the signal with this pitch name is regarded as the root tone for convenience and is sent to the OR circuit group 14.

This is to allow the bass accompaniment to progress without causing musical contradictions even if the chord name cannot be detected.
No particular details will be given. In addition, the same circuit 30 receives the one-key pressing method command signal 0F in the case of the one-key pressing method, and selects a single note name as the root note if multiple keys are pressed on the keyboard. It's getting old. In order to select a single note name, the same circuit 30 is constituted by, for example, a bass tone priority selection circuit (the C note side of the 12-tone scale is regarded as the bass tone).
The signal of the note name corresponding to the root note (root note selection signal) from the root note selection circuit 11 or the single note selection circuit 30 is sent to the OR circuit group 1.
4 to the same note name input side of the priority circuit 15.

From the one-tone selection circuit 30 or . The signal with the note name is given priority circuit 1.
5, the input signal passes through the same circuit 15 and a root note signal is generated on the output line of the note name.

In the root selection circuit 11, a plurality of logical expressions may be satisfied and a plurality of root selection signals may be generated. In this case, the priority circuit 115 selects only the signal of a single note name from among the plurality of root note names according to a predetermined priority (for example, bass priority), and outputs the root note signal to the output line of the single note name. Produces a sound signal. In this way, the priority circuit 15 always generates a root note signal on the output line of a single note name, thereby ensuring that only one chord name (or one root note name) is detected. Each output line of the priority circuit 15 is connected to a major third detection circuit 12,
They are respectively connected to the minor third detection circuit 13.

The circuits 12 and 13 detect whether or not a key having an interval of a major third or a minor third is pressed for the root note K1 detected and selected by the root note selection circuit 11 and the priority circuit 15. , the above detection is performed based on the output from the priority circuit 15 and the pressed key note name signal from the keyboard circuit 40. If a key with a major third interval relative to the root note is pressed, a major third interval detection signal 3 is generated, and if a key with a minor third interval is pressed, a minor third interval detection signal 3t1' is generated. occurs. Thus, the root note signal and each pitch detection signal 3F, 3, 5, 71' generated on the output line corresponding to the note name of the root note are used to identify and detect a certain chord name. However, in cases where the one-key press method or the detection circuit 10 cannot detect the chord name, the chord name is identified and detected only by the root signal from the one-note selection circuit 30. The root note signal sent from the chord name detection circuit 10 is input to the encoder 21.

That is, 12 output lines of each pitch name C-B corresponding to the root note are sent from the chord name detection circuit 10 to each encoder 21a.
~21f are respectively connected to the input sides. encoder 2
1, each note name is encoded in binary format into a specific numerical value corresponding to the pitch of each of the 12 note names C-B for a certain standard note name (for example, C note), C
If the note information is set to value 1 and is incremented by 1 for each semitone, the 12 note names C-B will have a value of 1 to 12 (4-bit 2).
digit information (binary code) is assigned to each. The root encoders 21a and 21f encode the root signal input into binary information representing the pitch name of the root, and the 3F degree encoder 21b
encodes the root note signal input into binary information representing the pitch name having a minor third interval for the root note, and below, the 3rd encoder 21c encodes the pitch name of the major 3rd interval, and the 5th encoder 21
d encodes the root note signal input into binary information representing the pitch name of a perfect fifth interval, and the 7v degree encoder 21e encodes the root note signal input into binary information representing the pitch name of a minor seventh interval. Therefore, each encoder 21a to 21
The structure of e is different for each note. For example, in an example where a numerical value from 1 to 12 is assigned to each note name, the root note encoder 2 is encoded based on the root note signal input of the same note name.
3-degree encoder 21b for encoded information 1a
The encode information is the value obtained by adding 3, 3 degree encoder 2
The encoded information of 1c is configured to be a numerical value added by 4, the encoded information of 5th encoder 21d is configured to be a numerical value added by 7, and the encoded information of 7th degree encoder 21e is configured to be a numerical value added by 10.

However, in this case, if the added value n exceeds 12, it is encoded as a value n-12. By the way, an example of encoded information is shown in the table below. Although the table shows the decimal value, the encoder 21 outputs the 4-bit 2 corresponding to this decimal value.
The system information is output. Thus, the code name detection circuit 10
When a root tone signal of a certain note name is added from , all notes (minor third, major third,
The encoders 21a to 21e simultaneously output binary information representing each note name (degree, perfect fifth, minor seventh interval),
It is added to the selection circuit 22.

The selection control unit 23 is a circuit for developing the tones (root note and subordinate note) constituting the chord detected by the detection circuit 10 for each single note (in a dispersed chord format) in a predetermined pattern of the bass accompaniment. According to the output from this circuit 23, the selection circuit 22
The selection of binary information from the encoders 21a to 21e is controlled.

That is, information from the root encoder 21a is selected by the root selection pulse P1, and subordinate selection pulses P3b, P
3, P, , P7b selects the information corresponding to the minor third, major third, perfect fifth, and minor seventh intervals from the encoders 21b to 21e. The rhythm pulse generator 24 is a circuit that regularly generates rhythm pulses Tl, T2, and T3, which determine the generation timing of the bass sound, every other time and according to a predetermined rhythm.
The generation timing of 3, that is, the type of rhythm, can be set arbitrarily.

The selection control section 23 appropriately selects the rhythm pulses T, ~T, depending on the presence or absence of each pitch detection signal 3, 3, 5, 7h from the chord ray name detection circuit 10, and selects the selection pulse P1.
~P, l7. form.

Selection pulses P1-P, h. For example, the logical formula for forming is as follows. Root selection pulse P, short 3
Degree interval selection pulse P, L length third interval selection pulse P, T2 ・3・5●71P・・・・・・・・・・・・・・・・・・
(7) Perfect fifth interval selection pulse P5 Minor seventh interval selection pulse P7llP In the selection control section 23, each of the above logical formulas (3) to (self)
A plurality of AND circuits are included to perform the following.

In addition, Ryoding, 100, 100, 7V are pitch detection signals 3ν, 3, 5
, 7ν does not occur. Note that the selection control unit 23 that receives the rhythm pulses T, -T3 selects rhythm pulses T1-T3 sent at a certain timing until a certain rhythm pulse T1-T3 is sent at the next timing. Temporarily held and converted into continuous non-interchronous held rhythm pulses HT, ~HT3, and the above logical formula (3)
The AND circuit may be configured by replacing the rhythm pulses T, ~T3 of -{11) with the holding rhythm pulses HTl~HT3.

In this way, when the selection pulses P1 to P and P are used in the circuits after the hold circuit 25 described later, a separate hold circuit is provided to hold the selection pulses, and the signals already held by the hold circuit 25 can be used. There is no need to synchronize. However, in this embodiment, since the selection pulses P1 to P and l7 are not used as described above, it is assumed for convenience of explanation that the pulses T1 to T are used as they are. According to the above logical formulas (3) to (11), the rhythm pulse is Tl
, T2, and T3 occur in order, then for a major chord, P1 → P, → P, or P, → P, for a minor chord, P, → P, l74 → P5, for a seventh chord, P1 → P , R→P, selection pulses are generated in the order.

The above describes the generation of the root tone subordinate selection pulse in the case of the multiple-key press method, but in the case of the single-key press method, the chord development (bass accompaniment pattern) setting signal Q is externally applied to generate the necessary selection pulse. Required logical formula (3) given the same conditions as when pitch detection signals 7t', 5, 3, 3b are added.
~ (self) has come to be satisfied.

When the single key pressing method command signal 0F is applied, selection pulses P, ~P7l7 are generated according to this setting signal Q, and when the same signal 0F is not applied, each pitch detection signal 3~P7l7 is generated from the detection circuit 10. Selective pulse P, ~ P, l according to 7
2 is generated.

The bass accompaniment pattern (the expanded form of the dispersed chord) is determined by the generation pattern of the root note/subordinate tone selection pulses P1 to P7ν as described above. As shown in FIG.
2 has gate circuits 22a to 22e that receive binary information from each encoder 21a to 21e, respectively, and
Each of the gate circuits 22a to 22e is controlled to open and close by root tone/following tone selection pulses P1 to P7ν corresponding to the pitch of each input binary information.

In the case of a major chord, first, the root note selection pulse P1 opens the gate circuit 22a at the timing of the rhythm pulse T1, selects binary information from the root note encoder 21a, and holds this information via OR circuits 221 to 224. Send on 25th. Next, the major third interval selection pulse P3 opens the gate circuit 22c at the timing of the rhythm pulse T2 and selects the binary information from the third encoder 21c. At the timing of the rhythm pulse T3, the perfect fifth interval selection pulse P opens the gate circuit 22d and selects the binary information from the fifth encoder 21d. In this way, binary information representing the note names of the root and subordinate notes of the chord is selected according to the desired bass accompaniment pattern. Since the binary information added to the hold circuit 25 is only one series and is 4 bits long, the circuit 25 only needs to have four hold circuits 251-254.

The hold circuits 251 to 254 are self-holding circuits that use memory elements such as flip-flops to feed back the output to the input side. At this time, a self-holding operation is performed. Therefore, when some binary information is applied to the hold circuit 25, this information is held in the same circuit 25 until the next time another binary information is applied.
In the case of the major chord, the binary information of the root note name inputted at the timing of the rhythm pulse T1 is held until the information of the note name of the major third interval is inputted at the timing of the rhythm pulse T2. As mentioned above, the hold circuit 25 (25
1 to 254) is required to be equal to the number of bits of binary information, which is considerably smaller than in conventional devices which require a hold circuit for each chord name (or root note name).

Further, the number of gates in the selection circuit 22 may be provided for each type of root note and subordinate note, and the encoder 21 may send binary information of the root note and subordinate note regarding a certain single chord name. Therefore, the gate circuits 22a to 22e for selecting information on the root note and subordinate notes of the same type (interval) are used in common regardless of the chord name. Therefore,
The number of gates is considerably smaller than in conventional devices, which require a large number of select circuits (gates) for each chord name to select signals corresponding to the root note and each subordinate note. The decoder 26 records the binary information added from the hold circuit 25 to the output lines C, C, .

The tone generator 27 is a circuit that generates a base tone signal with a frequency appropriate to the note name information added from the decoder 26, and may include an oscillator for each note frequency, multiple frequency dividing circuits, or a single frequency dividing circuit. Any configuration may be used, such as a configuration in which the frequency division ratio of the frequency dividing circuit can be varied in accordance with input of pitch name information. tone generator 2
The output of 7 is applied to an analog signal gate circuit 28, selectively sent out at the timing of generation of the bass tone generation control pulse BG, and generated as a bass tone via an appropriate sound system (not shown). The bass sound generation control pulse BG is generated from the rhythm pulse generating section 24 in synchronization with the generation timing of the rhythm pulses T, , T2, T3, so that the bass sound is generated by the rhythm pulses T, , T2, T3. It will be sounded in synchronization with the timing of occurrence. In both the multi-key pressing method and the single-key pressing method, bass accompaniment is automatically provided as described above.

O In the case of the multi-key pressing method, since multiple keys are pressed on the keyboard, it is possible to use a separate circuit (not shown) to simultaneously produce the sounds of these pressed keys and perform a chord.
In the case of the key press method, a circuit must be added to automatically play the chord. That is, root encoder 2
The output of 1b is applied to a hold circuit 61 for self-holding, decoded by a decoder 62, and a decoded output is supplied to an output line CB corresponding to the pitch name of the root note. This decoded output is applied to a root tone generator 63, a 3rd and 31P degree tone generator 64, and a 5th and 7th degree tone generator 65, respectively. The root tone generator 63 outputs a frequency signal corresponding to the pitch name of the inputted root tone.
Furthermore, the 3rd and 31'' degree tone generator 64 selectively outputs a frequency signal of a pitch name having an interval of a major third or a minor third with respect to the inputted root note, and is inputted from the outside. If the control signal R specifies a major chord, a frequency signal of a major third interval is output, and if the same signal R specifies a minor chord, a frequency signal of a minor third interval is output. The 7b degree tone generator 65 selectively outputs a frequency signal of a pitch name having a pitch of a perfect fifth or a minor seventh in response to the root note input, and the control signal S specifies the chord of the pitch of a fifth. If the signal S specifies a seventh chord, it outputs a frequency signal of a perfect fifth interval, and if the signal S specifies a seventh chord, it outputs a frequency signal of a minor seventh interval.

The output signals of each of the tone generators 63 to 65 are applied to gate circuits 66 to 68 for analog signals, respectively, and are passed through each of the gate circuits 66 to 68 at the generation timing of the chord sound generation control pulse CG to be used in an appropriate sound system (Fig. (not shown) and are simultaneously sounded as chord tones. The chord sound generation control pulse CG is for marking the sound generation timing of the chord sound, and is generated only when the rhythm pulse generator 24 or ・2 or 1 key press method is used, but the rhythm pulses T1 to T are special pulses. Not related. The present invention is not limited to a configuration in which the multiple key press method and the single key press method can be used in common as in the above embodiment, but the point is to convert information related to chord names into binary information. The bass accompaniment may be progressed based on this binary information. Therefore, the configuration of the chord name detection circuit 10, etc., and the types of chords that can be detected are not limited to the above embodiments. Furthermore, not only when playing a chord by directly pressing four keys on a keyboard, but also when automatically playing a chord by reading information from a perforated tape, etc., the name of the chord being played can be detected and the above embodiment can be used. Similarly, bass accompaniment can be applied. In addition, in the above example, the root note,
Encoders 21a to 21e are provided for each of the minor third interval (3rd degree), the major third interval (3rd degree), the perfect fifth interval (5th degree), and the minor seventh degree (7th G degree). Root tone, 3 degrees, 3 degrees, 5 degrees, 717 degrees encoder 21a~
Although the configuration is such that the output from one of the encoders 21e is selected, the present invention is not limited to this, and similar effects can be obtained by combining the root encoder 21a and the adder. That is, only a single root encoder 21a is provided as an encoder, and an adder converts the output of the encoder 21a into a numerical value according to a command from the selection control section 23 (when commanding 3 degrees, the numerical value 3 is set). It can be implemented in the same manner as in the above embodiment by adding the numerical value 4 for 3 degrees, the numerical value 7 for 5 degrees, and the numerical value 10 for 75 degrees. In this case, the encoder 21b to
This is similar to the case of 21e. As described above, according to the present invention, the number of hold circuits and selection circuits can be reduced, and the miniaturization of circuit devices and the use of ICs can be promoted.

Furthermore, since the chip size of the IC circuit is reduced, the reliability of the 1C circuit is improved, making it ideal for IC implementation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the automatic accompaniment apparatus of the present invention, and FIG. 2 is a block diagram showing essential parts of the same embodiment. 10... Code name detection circuit, 21...
Encoder, 22... Selection circuit, 22a-22
e...Gate circuit, 221-224...
・OR circuit, 251-254...Hold circuit, 250, N0R...NOR circuit.

Claims (1)

[Claims] 1 A circuit that detects the name of the chord being played; a circuit that outputs a note name signal representing the root note in response to the detection of the chord name; and a circuit that inputs the note name signal representing the root note and converts it to the root note and root note. On the other hand, an encoder that forms binary information representing each pitch name of a plurality of subordinate tones in a predetermined interval relationship, and an encoder that generates binary information of the root note and binary information of the subordinate note corresponding to the detected chord name at appropriate timing. An automatic accompaniment device comprising a selection circuit for selectively sending out a selection and a circuit for generating a bass tone based on the selected binary information.