JPS6025096Y2 - automatic accompaniment device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improved automatic accompaniment device that periodically changes chord tone or bass tone.

Various automatic accompaniment devices have been proposed in the past, but all of them have the disadvantage that the timbre of the accompaniment sound is constant and the automatic accompaniment itself becomes monotonous.

The purpose of this invention is to eliminate such drawbacks and to provide a new type of automatic accompaniment device that can periodically change the timbre of an accompaniment tone, for example, every one or more bars.

This invention is an automatic accompaniment device that automatically generates accompaniment sounds such as chord tones and bass tones by detecting the depression of a key-shaped key. b
) a memory circuit whose state changes every time a pulse signal synchronized with the rhythm pattern signal arrives, and which generates a tone switching signal according to the memory state; The present invention is characterized in that it includes a switching control means for switching and controlling the timbre of the accompaniment sound.

According to the configuration of this invention, since the memory circuit such as the T-flip-flop is driven by a pulse signal synchronized with the rhythm pattern signal, during the period from generation of one pulse signal to generation of the next pulse signal, The state of the timbre switching signal is constant, and timbre control is continuously performed from attack to decay for each accompaniment note.

Therefore, the timbre becomes clear, and it is possible to realize a timbre change that is audibly preferable as a periodic accompaniment sound change.

This invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

FIG. 1 shows an automatic accompaniment device according to an embodiment of this invention.

A sound source signal corresponding to each scale note generated from the sound source circuit 10 is opened and closed in an opening/closing circuit 14 in accordance with an output signal of a key switch circuit 12 including a key switch that closes in response to a key press, and a chord sound gate is generated. The signal is sent to circuit 20.

On the other hand, the state of the key switch closed corresponding to, for example, a chord of C, E, or G is detected by the root note detection circuit 16, and the state of the key switch that is closed corresponding to a chord of C, E, or G is detected by the root note detection circuit 16, A key-on signal corresponding to the sound) is generated.

1 in the bass sound opening/closing circuit 18 in response to this key-on signal.
Sound source signals corresponding to a degree tone (C note) and a fifth note (G note) are opened and closed, and are sent to the first degree gate circuit 24 and the fifth degree gate circuit 26, respectively.

On the other hand, in the rhythm pulse generation circuit 31, a selected one of rhythms such as waltz, rumba, mambo, etc.
Rhythm pattern signals 31a, 3 corresponding to
1bt 31c is generated and these signals 31a, 3
lb and 31c are chord tone gate circuits 20.1, respectively.
Degree gate circuit 24.5 degree gate circuit 26 is applied as a control signal.

Each time the rhythm pattern signal pulse arrives, the gate circuits 20, 24, 26 output musical tone signals 20a and 1st degree tone (CEG) corresponding to the chord tone (CEG).
), and a musical tone signal 26a corresponding to a fifth (G) are output, respectively.

That is, these musical tone signals 20a, 24a, and 26a are generated according to a rhythm pattern set in the rhythm pulse generation circuit 31.

The musical tone signal 20a is sent to a chord variable tone color circuit 22 and given a predetermined tone characteristic.

Furthermore, the musical tone signal 24at 26a is also sent to the bass variable timbre circuit 28 and given a predetermined timbre characteristic.

The timbre characteristics of the timbre circuits 22 and 28 are controlled by a unique circuit arrangement according to this invention, which will be described later.

Here, to briefly explain the rhythm pulse generation mechanism in the rhythm pulse generation circuit 31, this circuit 31 consists of a counting circuit 3 that outputs sequential pulses for two measures in parallel.
2, a rhythm pattern generation circuit 34 having a ROM etc. driven by the parallel sequential pulses and generating pulse signals corresponding to several rhythm patterns; It includes a selector circuit 36 that selects and outputs.

The counting circuit 32 includes a counter that counts clock pulses from the clock pulse generator 30 having a frequency adjustment variable resistor 30a, and a decoder that decodes the parallel output of this counter and outputs sequential pulses for two bars in parallel. It is equipped with

Which rhythm pattern signal should be selected by the selector circuit 36 can be appropriately set using a rhythm selection switch 38.

The rhythm pattern signal of the selector circuit 36 is the rhythm sound source 4.
The rhythm sound source 40 generates rhythm sound signals corresponding to percussion instrument sounds such as bass drums, snare drums, cymbals, etc., in accordance with the rhythm pattern signal.

Musical tone output from timbre circuit 22.28 and rhythm sound source 40
Rhythm sound signals from variable resistors VRI and VR2, respectively.
The mixed signals are mixed at an appropriate ratio via the VR 3 and then guided to an electro-acoustic converter 50 such as a speaker via an amplifier 48, where they are produced as accompaniment sounds.

Here, the control system for controlling the timbre characteristics of the timbre circuits 22 and 28 will be explained. This control system uses a pulse signal 32a that instructs the start of the first bar, and a pulse signal 32a that instructs the start of the second bar. 32b is input 2
A manual OR gate, a tone change timing selection switch 44 whose fixed contact a receives the output signal of the OR gate 42, and whose fixed contact receives the pulse signal 32a, and an output from the movable contact of this switch 44. A T-flip-flop 46 receives a trigger (T) input and generates a tone switching signal 46a consisting of an output Q.

Now, assuming that the input is applied to the flip-flop 46 via the contact a side of the switch 44, the flip-flop 46 inverts its state every time the pulse signals 32ay32b change from low level to high level, and the output Q becomes 1. The amplitude level changes for each bar.

Furthermore, when the flip-flop 46 is triggered via the contact side of the switch 44, the output Q of the flip-flop 46 has an amplitude level that changes every two bars.

In this way, depending on whether the switch 44 is set to the contact a side or the contact side, a timbre switching signal with an amplitude level change every one bar or a timbre switching signal with an amplitude level change every two bars can be obtained. You can choose to get as much as you want.

No matter which tone color switching signal is obtained, two types of tone color switching can be performed according to changes in the amplitude level.

That is, the timbre circuit 22 has its timbre characteristics changed periodically by the timbre switching signal 46a every 1 or 2 bars, and the timbre circuit 28 also changes its timbre characteristics by 1 by the timbre switching signal 46a.
Or it changes periodically every two measures.

FIG. 2 illustrates a variable filter circuit that can be used in these tone color circuits, and each tone color circuit 22.2
In No. 8, by using this type of variable filter circuit, it is possible to easily obtain a timbre change in response to a periodic binary signal.

Here, to briefly explain the circuit shown in FIG. 2, this circuit receives a musical tone signal inputted to an input terminal 60 through an emitter follower transistor operated by a power supply voltage -■.
2, two types of CR filters provided at the emitter output of this transistor are selectively acted on by switching elements G1 and G2 such as the lower ET, and the output terminal is connected to the output terminal via either one of the CR filters. 66 to obtain musical tone output.

One CR filter consists of a parallel circuit of a resistor R1 and a capacitor C1, and is connected in the circuit when the switching element G1 is on.

The other CR filter consists of a parallel circuit of a resistor R2 and a capacitor C2, and is connected in the circuit when the switching element G2 is on.

Tone switching signal 4 consisting of output Q of flip-flop 46
6a is applied to the control input terminal of the switching element G1 and the input terminal of the inverter 64, and the output of the inverter 64 is applied to the control input terminal of the other switching element G2.

If the signal 46a is now at a high level, the switching element G1 is turned on, and when the signal 46a is at a low level, the switching element G2 is turned on.

Due to the alternate ON operation of switching elements Gl and G2, one of the CR filters is connected in the circuit, and the output terminal 66 receives different frequency components depending on which CR filter is connected in the circuit. A rich musical tone signal can be obtained.

The alternate ON operation of switching elements Gl and G2 is signal 4.
6a, so that when the musical tone signal obtained at the output terminal 66 is generated, the timbre of the musical tone changes periodically every 1 or 2 measures. Become.

Although this invention has been described above in detail with reference to examples, it will be clear that this invention is not limited to the above-mentioned examples and can be implemented in various modified forms.

For example, a voltage controlled variable filter (VCF) may be used as the tone color circuit 22,28.

Further, the means for changing the timbre is not limited to the above-mentioned method using a timbre filter, but a method of switching the waveform of the sound source signal can also be used instead of or in addition to it.

Furthermore, in the above embodiment, two types of timbres are switched, but the timbre circuit has three or more timbre control units, and a ring counter or the like is used instead of a T-flip-flop to generate a timbre switching signal. If you do this,
It is also possible to switch between three or more types of tones.

According to this invention, the timbre of the accompaniment can be changed periodically for each bar or for each bar, so the monotony of automatic accompaniment can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an automatic accompaniment device according to an embodiment of the invention, and FIG. 2 is a circuit diagram showing a variable tone color circuit used in the device of FIG. 22... Variable tone circuit for chords, 28...
...Variable tone color circuit for bass, 44...Switch for selecting tone change timing, 46...T-flip-flop for generating tone change signal.

Claims (1)

[Scope of Claim for Utility Model Registration] In an automatic accompaniment device that detects keys pressed on a keyboard and automatically generates accompaniment sounds such as chord tones and bass tones, (a) a device that generates rhythm pattern signals; and (b
) a memory circuit whose state changes every time a pulse signal synchronized with the rhythm pattern signal arrives, and which generates a tone switching signal according to the memory state; An automatic accompaniment device comprising a switching control means for switching and controlling the tone of an accompaniment tone.