JP2000206971A - Arpeggiater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an arpeggiater generating a real arpeggio sound. SOLUTION: Attenuating input signals showing respective musical sounds of a composition are converted freely to lasting signals by a hold circuit 20, and the pitches of the signals outputted from the hold circuit 20 are shift-ed by a pitch shift amount decided based on the interval of the arpeggio sound shown by the frequency, the tune set by a tune setting part 33 and the pitch of the input signal detected by a pitch detection part 34 stored in a pitch shift control part 32 at the timing of prescribed once or above by a pitch shift processing part 31, and the envelope of the shifted signal is deformed by an envelope processing part 51 at the timing the same as respec-tive timing, and an attack is given.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arpeggiator for sequentially shifting an input signal to a different pitch and outputting the resulting signal.

[0002]

2. Description of the Related Art Conventionally, there is provided an input section for inputting a sound generated by playing a musical instrument such as a guitar, and a chord is shifted by shifting a pitch of a sound input from the input section according to a series of intervals. There is known a device called an arpeggiator which automatically generates an arpeggio sound composed of a series of sounds in which a plurality of constituent sounds are sequentially played one by one. In general, it is difficult to generate an arpeggio sound by playing one note at a time using a natural musical instrument or the like.
When playing arpeggio sounds one by one with a guitar, it is required to play several strings quickly in a predetermined order. However, by using the arpeggiator as described above, a plurality of tones constituting the arpeggio sound are automatically generated just by pressing a single string and playing the string once, so that the performer includes the arpeggio sound. Music can be played by simple performance operations. Further, as described above, this arpeggiator receives a sound generated by playing a musical instrument such as a guitar, and generates an arpeggio sound using the input sound, so that it is possible to generate an arpeggio sound with good sound quality. it can.

[0003]

However, in the above-described arpeggiator of the prior art, the pitch of the input sound is merely changed, and the arpeggio sound generated by the arpeggiator is used for musical instruments such as guitars. However, there is a problem in that there is a great difference in the sense of hearing and a lack of reality as compared with the arpeggio sound actually played one by one.

The present invention has been made in view of the above circumstances, and has as its object to provide an arpeggiator capable of generating a realistic arpeggio sound.

[0005]

An arpeggiator according to the present invention for achieving the above object comprises: (1) an input section to which an input sound having a pitch is input; and (2) a shift of a pitch of an input sound input from the input section. A pitch shift processing unit in which the amount of shift changes at a predetermined timing; and (3) an envelope processing unit for applying a predetermined deformation to the envelope of the input sound input from the input unit at the predetermined timing. And

Here, the "predetermined deformation" refers to a deformation in which a mountain-shaped envelope is added, such as increasing at the above timing, having a peak, then attenuating and trailing.

In the arpeggiator of the present invention, the above (1)
The pitch of the input sound input to the input unit is shifted by the pitch shift processing unit (2), and the shifted amount changes at a timing corresponding to the sounding timing of each sound constituting the arpeggio sound. . Further, in the envelope processing unit of (3), a process of applying a predetermined deformation to the envelope of the input sound is performed at the same timing as the timing, and an envelope corresponding to the start of each sound of the arpeggio sound is performed. However, the envelope is a so-called attack, which simulates a portion having a large amplitude of a sound actually generated by a guitar or the like. Therefore, each sound constituting the arpeggio sound generated by the arpeggiator of the present invention has a strong starting portion, and each sound is heard as an independent sound, and a realistic arpeggio sound is generated.

In the arpeggiator of the present invention, it is preferable that the pitch shift processing section shifts the pitch of the input sound input from the input section by a shift amount corresponding to the pitch of the input sound.

In general, music is played under a certain key,
The tone determines the impression of the song. Further, each pitch of each musical tone constituting a musical piece performed under a certain key follows a predetermined order. For this reason, if the music is played using the arpeggiator that shifts the pitch by a predetermined shift amount regardless of the pitch of the input sound, the order in which the pitch of the music sound follows the music may be disrupted, and the impression of the music may be broken. .

The arpeggiator having the preferred configuration described above shifts the pitch of the input sound by a shift amount corresponding to the pitch of the input sound in (1). Therefore, the arpeggio sound generated by the arpeggiator having this preferred configuration is in harmony with the music.

Further, the arpeggiator of the present invention comprises: (4) a key setting section for setting a key, and the pitch shift processing section of (2) comprises:
It is preferable that the pitch of the input sound input from the input unit is shifted by a shift amount corresponding to both the key set by the key setting unit and the pitch of the input sound.

In the arpeggiator having such a configuration, the pitch shift processing section of (2) is adapted to input an input sound to the input section of (1) in accordance with the key set by the key setting section of (4). Shift pitch. Therefore, when a plurality of arpeggio sounds are generated by the arpeggiator having such a configuration, the arpeggio sounds are harmonized under the key set by the key setting unit of (4).

[0013] The arpeggiator of the present invention preferably comprises (5) a hold section for holding the input sound input from the input section.

In the arpeggiator having such a configuration, when an attenuated sound that attenuates over time is input to the input unit of (1), the hold unit of (5) accepts the attenuated input sound. Hold. As a result, the input sound is a sound having a constant amplitude or a sound with a smaller attenuation than the input sound. Therefore, even if the input sound input to the input unit in (1) is a sound that attenuates with time, such as a guitar sound, it is necessary to generate a sufficiently large sound up to the last sound constituting the arpeggio sound. Can be.

[0015]

Embodiments of the present invention will be described below.

FIG. 1 is a block diagram showing one embodiment of the arpeggiator of the present invention.

The arpeggiator 1 converts the pitch of an input signal representing each musical tone of a musical piece played by a so-called electric guitar or the like into the pitch of each tone constituting the finally generated arpeggio tone as described below. Pitch shift based on the input signal, and further deforms the envelope of the input signal with the addition of a mountain-shaped envelope, and outputs a signal in which the pitch shift and the deformation of the envelope are performed as an output signal. .

FIG. 2 shows an example (A) of an input signal input to the arpeggiator shown in FIG. 1, a signal (B) in which the pitch of the input signal is shifted, and an output from the arpeggiator according to the input signal. 4 is a graph showing an output signal (C).

Hereinafter, FIG. 1 will be described with reference to FIG.

More specifically, the input signal is one of a plurality of sounds sequentially generated by striking the strings one by one.
Represents one sound that decays. FIG. 2A shows the state of the input signal representing one sound. The upper graph of FIG. 2A shows the envelope of the amplitude of the input signal, and the lower graph of FIG. 2A shows the pitch of the input signal. Since the input signal is a string vibration signal, the input signal actually has a slight pitch variation that cannot be recognized as a pitch change, but such a pitch variation is ignored in this drawing. Is shown. The horizontal axis of each graph represents time, the vertical axis of the upper graph of FIG. 2A represents the signal level, and the vertical axis of the lower graph of FIG. 2A represents the signal pitch. As shown in the upper graph of FIG. 2A, the level of this input signal starts increasing at time 0, reaches a peak at time tp, and then decreases. In addition, since a portion representing one tone of the input signal is considered here, the pitch of the input signal does not change over time as shown in the lower graph of FIG. Note that, at times t1, t2, t3, t4, and t5 in FIG.
Indicates the timing at which the arpeggiator 1 generates each sound constituting the arpeggio sound.

The arpeggiator 1 is provided with an input terminal 10, and the above-described input signal is input to the input terminal 10. That is, the input terminal 10 corresponds to the input unit according to the present invention. The arpeggiator 1 is provided with a hold circuit 20, and an input signal input to the input terminal 10 is input to the hold circuit 20. The hold circuit 20 is provided with a switch for switching the circuit on and off.
Converts an attenuating input signal into a signal having a continuous amplitude and outputs the signal. The details of this conversion will be described later. Hereinafter, a case where the switch of the hold circuit 20 is off will be described for convenience of description. In this case, the input signal passes through the hold circuit 20.

The signal output from the hold circuit 20 is input to a pitch shift processing section 31. The pitch shift processing unit 31 receives the control signal indicating the absolute pitch shift amount, and shifts the pitch of the signal input to the pitch shift processing unit 31 by the absolute pitch shift amount. This shift amount changes sequentially each time the control signal is received, and the signal generated by shifting in this manner represents the arpeggio sound.

As described above, the pitch of the input signal passing through the hold circuit 20 is shifted and output by the pitch shift processing unit 31 based on the control signal indicating the information of the absolute pitch shift amount. The state of the output signal is shown in FIG. The upper graph in FIG. 2B shows the envelope of the amplitude of this signal, and the lower graph in FIG. 2B shows the pitch of this signal. The horizontal axis of the graph in FIG. 2B represents time. The vertical axis of the upper graph in FIG. 2B represents the signal level, and the vertical axis of the lower graph in FIG. 2B represents the signal pitch. The pitch shift processing unit 31 does not perform any processing on the envelope of the input signal. Therefore, FIG.
The envelope shown in the upper graph of FIG.
This is exactly the same as the envelope of the input signal shown in the upper graph of (A). On the other hand, as shown in the lower graph of FIG. 2B, the pitch of the pitch-shifted sound signal is
It changes at times t1, t2, t3, t4, and t5. Each of the changed pitches is output to the pitch shift processing unit 31.
Corresponds to the absolute pitch shift amount represented by the received control signal, and the signal thus shifted in pitch represents an arpeggio sound. Times t1, t2, t3, t
4, t5 are times when the pitch shift processing unit 31 receives the control signal.

The control signal input to the pitch shift processing section 31 is generated by the pitch shift control section 32.
It should be noted that both the pitch shift control unit 32 and the pitch shift processing unit 31 of the present embodiment constitute a pitch shift processing unit according to the present invention.

The pitch shift control unit 32 has an arpeggiator phrase table in which the pitch shift amount corresponding to each sound constituting the arpeggio sound is defined in frequency units. Reads the pitch shift amount expressed in units. Here, the frequency is a unit for expressing a difference in pitch between sounds based on human senses. The arpeggiator 1 includes a key setting unit 33 and a pitch detecting unit 34.
In 3, the key is set by the player of the musical instrument, and the pitch detector 34 detects the pitch of the input signal. The pitch shift control unit fetches the set key from the key setting unit 33 and fetches the detected value of the detected pitch of the input signal from the pitch detection unit 34. Further, the pitch shift control unit 32
Has an intelligent pitch shift table, which will be described later, and determines an absolute pitch shift amount by referring to the intelligent pitch shift table based on a pitch shift amount expressed in units of degrees. Details of the determination of the absolute pitch shift amount will be described later.

A control signal for transmitting the absolute pitch shift amount to the pitch shift processing unit 31 is transmitted to the pitch shift control unit 3.
2 is output from the timing management unit 40.
Is managed by The timing management unit 40 detects the start of an input signal representing one tone, and uses the time of the start as a reference, at the timing of each time interval designated by a knob or the like not shown in FIG. And outputs a trigger for a signal indicating the start of sound generation of each of the sounds constituting. Then, every time the trigger is input, the pitch shift control unit 32 outputs a control signal indicating the absolute pitch shift amount.

The signal output from the pitch shift processing unit 31 is input to the envelope processing unit 51. The envelope processing unit 51 receives a control signal representing an additional envelope imitating the attack of the guitar sound, adds the additional envelope to the envelope of the signal output by the pitch shift processing unit 31, and outputs an output signal.

The control signal input to the envelope processing unit 51 is output by the envelope control unit 52. Note that the envelope control unit 52 and the envelope processing unit 51
Both constitute the envelope processing unit according to the present invention. The envelope control unit 52 stores the shape of the additional envelope, and upon receiving a trigger from the timing management unit 40, outputs a control signal representing the additional envelope.

FIG. 2C shows the state of the output signal output from the envelope processing section 51. The upper graph of FIG. 2C shows the envelope of the amplitude of the output signal, and the lower graph of FIG. 2C shows the pitch of the output signal. The horizontal axis of the graph in FIG. 2C represents time. The vertical axis of the upper graph of FIG. 2C represents the signal level, and the vertical axis of the lower graph of FIG. 2C represents the signal pitch.

As shown in the upper graph of FIG. 2C, this output signal includes peaks starting at times t1, t2, t3, t4, and t5 corresponding to the start of each sound constituting the arpeggio sound. Envelopes p1, p2, p
3, p4, and p5, and these mountain-shaped envelopes p1, p2, p3, p4, and p5 represent the additional envelopes added by the envelope processing unit 51. In addition, the envelope processing unit 51 includes the envelope processing unit 5.
No processing is performed on the pitch of the signal input to the input signal No. 1, and the pitch of the output signal output by the envelope processing unit 51 shown in the lower graph of FIG. ) Is the same as the pitch in the signal output by the pitch shift processing unit 31 shown in the lower graph. The output signal shown in FIG. 2C is finally output from the arpeggiator 1.

The above is the configuration in the present embodiment and the state of signal processing in the present embodiment. Based on the signal finally output from the arpeggiator 1, the starting portion of each sound is strong by a speaker or the like, and a realistic arpeggio sound is produced as if each sound were played one by one.

Next, regarding the details of the determination of the absolute pitch shift amount in the pitch shift control unit 32 omitted above, the intelligent pitch shift table and the arpeggiator phrase table used in the process of this determination will be described. Description will be given with reference to each example.

Table 1 shows the intelligent pitch shift
4 shows an example of a table.

Table 2 shows an example of the arpeggiator phrase table.

[0035]

[Table 1]

[0036]

[Table 2]

The pitch shift control unit 32 uses an intelligent
Refer to the pitch shift table. This table is
Each of them has C, C #, D, D #, E, F, F #,
A total of 12 types of keys with G, G #, A, A #, B
It is prepared for each type. From the key setting section 33, the key of the music to be played, which is set by the player, is obtained, and a table corresponding to the key is selected. Here, a case will be described in which the key setting section 33 sets the C major key having C as a main tone. At this time, a table for C major having C as a tonic shown in Table 1 is selected from the above 12 kinds of tables. C, C #,
The symbols D, D #, E, F, F #, G, G #, A, A #, and B represent the pitch of the input signal detected by the pitch detector 34. The numbers from -8 to 8 in the leftmost column of this table represent the pitch shift amount of the arpeggio sound specified in units of frequency. The numbers from -12 to 12 shown in the rest of the table represent the absolute pitch shift amount. The unit of these absolute pitch shift amounts is 100 cents. This 100 cents corresponds to a semitone, and 1200 cents corresponds to one octave.

Further, the pitch shift control unit 32 reads a pitch shift amount represented by a frequency corresponding to each sound constituting the arpeggio sound from the arpeggiator phrase table. Table 2 shows an example of the arpeggiator phrase table. In the upper part of Table 2, the numbers of the steps corresponding to the sounds constituting the arpeggio sound are shown. For example, the step with the number “3” corresponds to the time period from time t2 to time t3 in FIG. are doing. The lower part of Table 2 shows the pitch shift amount expressed in degrees at each step of the upper part. Each pitch shift amount shown here is the same as that shown in FIG.
Corresponds to each pitch shift amount at each time t1 to t6.

For example, between time t2 and time t3,
The pitch shift amount is 3 degrees. The absolute pitch shift amount corresponding to the three pitch shift amounts should be determined according to the pitch of the input signal, and is 300 cents.
May be appropriate, or 400 cents may be appropriate. The input terminal 10
When it is detected that the pitch of the input signal that is input to is the pitch corresponding to, for example, the sound “F”, the pitch shift control unit 32 displays “F” at the top of the table in Table 1. The value "4" indicating the absolute pitch shift amount is obtained in the column existing at the position where the column and the row indicated by "3" in the leftmost column intersect. Thereby, the pitch shift control unit 32 sets the absolute pitch shift amount to 400 ce.
nt.

In this way, for any pitch shift amount defined in degrees, the absolute pitch shift amount according to both the set key and the pitch of the input signal can be determined. Based on the absolute pitch shift amount, the pitch shift processing unit 31 causes the hold circuit 20
The pitch of the signal output from is shifted. And
The sound represented by the signal whose pitch is shifted by the absolute pitch shift amount described above is also in harmony with the music to which the sound belongs.

Finally, a description will be given of the hold circuit 20 which has been omitted earlier. As described above, the hold circuit 20 holds the attenuated input signal and outputs a continuous signal.

FIG. 3 is a graph showing an input signal input to the hold circuit and a signal output from the hold circuit.

The upper graph of FIG. 3 shows the envelope of the input signal, which is the same as the envelope of the waveform of the input signal shown in FIG.
The lower graph of FIG. 3 shows the envelope of the signal output by the hold circuit 20. The horizontal axis in FIG. 3 indicates time, and the vertical axis indicates the volume level. The envelope of the input signal has a peak at time tp, and thereafter,
Hold circuit 20
The envelope indicated by the waveform of the signal output by has a peak at time tp and then attenuates to a certain magnitude.
Since then it has been maintained at that size. By maintaining the size of the envelope in this way, it is possible to prevent the arpeggio sound from becoming narrow.

The basic idea of this conversion is to sample the input signal for a predetermined time t and repeat the sampled signal. However, the discontinuity of the volume occurs in the signal which is simply repeated as described above, and the discontinuity is avoided by modulating this signal using a triangular wave and the like. Hereinafter, the state of the conversion will be described in detail together with the configuration of the hold circuit 20.

FIG. 4 is a circuit diagram of the hold circuit.

The hold circuit 20 includes a first hold switch 211, a second hold switch 212, a delay line 220, a cross-fade waveform generator 230,
, A second multiplier 242, and an adder 250. This delay line 220
It has two read points TAP1 and TAP2, and the cross-fade waveform generator 230 has two output terminals w
1 and w2. Hereinafter, these components will be described, and signals processed by these components will be described with reference to FIG.

FIG. 5 is a diagram showing the signals (A) and (B) output from the delay lines provided in the hold circuit and the triangular signals (C) and (D) for amplitude-modulating the signals.

First, the first hold switch 31 shown in FIG.
The case where 1 is off will be described. In this case, the input signal is input to the hold circuit 20. The envelope of the waveform of this input signal is shown in the upper graph of FIG.

In the hold circuit 20, the first hold switch 211 and the second hold switch 212 are linked. Therefore, the input signal is supplied to the first multiplier 241
, And also to the second multiplication unit 242.

On the other hand, the crossfade signal generator 2 shown in FIG.
30 generates a triangular wave WAVE1 and a triangular wave WAVE2. FIG. 5 (C) shows an example of the triangular wave WAVE1, and FIG. 5 (D) shows an example of the triangular wave WAVE2. In FIGS. 5C and 5D, the horizontal axis represents time, and the vertical axis represents signal magnitude. These two triangular waves are
It has a peak alternately every time t / 2, and when added together, it becomes a signal having a constant amplitude of magnitude 1.

The first multiplier 241 and the second multiplier 24
1 is subjected to the amplitude modulation of the triangular wave WAVE1 by the first multiplier 241 and the second multiplier 24
2, the amplitude modulation of the triangular wave WAVE2 is performed, and the two signals subjected to the amplitude modulation are added to each other by the adder 250. As a result, the same signal as the original input signal is output.

Next, the first hold switch 21 shown in FIG.
The case where 1 is on will be described. In this case, the input signal is not input to the hold circuit 20. Then, a loop passing through the delay line 220 is formed in the hold circuit 20, and a signal sampled by the delay line 220 over a time t continues to go around this loop. The signal that continues to go around this loop is read at the read point TAP1 of the delay line 220, and the signal TAP1-OU is read.
T is output, and at the read point TAP2, the signal is read and the signal TAP2-OUT is output.

FIG. 5A shows an example of the signal TAP1-OUT, and FIG. 5B shows an example of the signal TAP2-OUT. 5A and 5B, the horizontal axis represents time, and the vertical axis represents signal magnitude. Signal TAP1-OU
T and the signal TAP2-OUT are both the delay line 2
Since the signal sampled and cut at time interval t by 20 is read out, it is a signal having a period of time t and discontinuity occurs in amplitude.

On the other hand, the cross-fade signal generator 230
Generates a triangular wave WAVE1 and a triangular wave WAVE2 when the hold switch is on, as in the case where the hold switch is off.

The signals TAP1-OUT, TAP2-O
The UT is input to the multipliers 241 and 242. Further, the triangular waves WAVE1 and WAVE2 are input to the multipliers 241 and 242, and the signals TAP1-OUT and TAP2-OUT
Is subjected to amplitude modulation by the multipliers 241 and 242, and its envelope becomes a triangular wave. At this time, the signals subjected to the amplitude modulation are signals TAP1-OUT and TAP2-OUT.
Since the amplitude is zero at the point where the amplitude discontinuity point occurs at OUT, no discontinuity occurs. The signal subjected to the amplitude modulation is output by the multiplier.

The signal output from the first multiplier 241 and the signal output from the second multiplier 242 are added by the adder 250. Since the signals output from the two multipliers have peaks alternately, the added signal has a substantially constant amplitude. This signal is output from the hold circuit 20. Since this signal is a signal obtained by adding two signals having the same frequency as the input signal by the adder 250, the frequency is also equal to the frequency of the input signal.

However, the time sampled by the delay line 220 and the read points TAP1, TAP
When 2 is fixed, depending on the frequency of the input signal, when the signal output from the first multiplier 241 and the signal output from the second multiplier 242 are added by the adder 250, The signals may cancel each other out, resulting in an unnatural amplitude modulation. In order to avoid such unnatural amplitude modulation, the delay line 220 includes
Means for adjusting the line length t is provided, and the line length is adjusted in accordance with the pitch of the signal input to the delay line 220.
TAP2 is also adjusted.

In the above embodiment, after the input signal is subjected to the pitch shift processing, the pitch-shifted signal is subjected to the envelope processing. However, in the present invention, the input signal is subjected to the envelope processing. After the processing, the signal subjected to the envelope processing may be subjected to a pitch shift processing.

In the present invention, a digital signal may be input as an input signal, and the input signal may be subjected to digital signal processing.

[0060]

As described above, according to the arpeggiator of the present invention, a real arpeggio sound is generated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of an arpeggiator of the present invention.

FIG. 2 shows an example of an input signal (A) input to the arpeggiator shown in FIG. 1, a signal (B) in which the pitch of the input signal is shifted, and an output output from the arpeggiator according to the input signal. It is a graph which shows a signal (C).

FIG. 3 is a graph showing an input signal input to a hold circuit and a signal output from the hold circuit.

FIG. 4 is a circuit diagram of a hold circuit.

FIGS. 5A and 5B show examples (A) and (B) of a signal output from a delay line provided in a hold circuit, and examples (C) and (D) of a triangular wave signal for amplitude-modulating the signal. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Arpeggiator 10 Input terminal 20 Hold circuit 31 Pitch shift processing part 32 Pitch shift control part 33 Key setting part 34 Pitch detection part 40 Timing management part 51 Envelope processing part 52 Envelope control part 211 First hold switch 212 Second hold switch 220 delay line 230 cross-fade waveform generator 241 first multiplier 242 second multiplier 250 adder

Claims (4)

[Claims] 1. An input unit to which an input sound having a pitch is input, and shifting a pitch of the input sound input from the input unit,
A pitch shift processing unit that changes the shift amount at a predetermined timing; and an envelope processing unit that applies a predetermined deformation to the envelope of the input sound input from the input unit at the predetermined timing. Arpeggiator. 2. The apparatus according to claim 1, wherein the pitch shift processing section shifts a pitch of the input sound input from the input section by a shift amount corresponding to the pitch of the input sound. Arpeggiator. 3. A key setting unit for setting a key, wherein the pitch shift processing unit sets a pitch of an input sound input from the input unit to a key set by the key setting unit and a pitch of the input sound. 2. The arpeggiator according to claim 1, wherein the shift is performed by a shift amount corresponding to both of the above. 4. The arpeggiator according to claim 1, further comprising a hold section for holding the input sound input from said input section, wherein said input sound is an attenuated sound that attenuates with time.