JPH04133095A - Tempo controller - Google Patents

Abstract

PURPOSE:To smoothly follow up the output of automatic performance at the time of tapping by eliminating a time difference (deviation) in score time, which is generated at the time of the tapping, with a certain function. CONSTITUTION:A tempo clock is supplied from the tempo controller 1 to a sequencer 2 through an MIDI cable. At this time, the quantity of the deviation in score time at the time of the tapping is found and reduced according to the specific function. Then performance data are read out of the performance data memory in the sequencer 2 according to the tempo clock and sent to a sound source 3. Waveform data corresponding to the performance data are read out of the sound source memory of the sound source 3 and outputted to a sound system 4. Then while the score time deviation quantity is reduced according to the specific function, the current score time is updated. Consequently, the output of automatic performance at the time of the tapping can smoothly be followed up.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a tempo controller that can provide a tempo clock controlled in real time to a sequencer, rhythm machine, or the like.

(b) Conventional technology One of the most important basic elements of music is the tempo of performance. The tempo changes in various ways even during the performance of a single song, and plays a major role in creating the expression of the song. These tempo changes include a variety of things, such as global tempo changes like ritardando and accelerando, and small tempo fluctuations within a measure. If you can make subtle changes in tempo with child instruments, especially when playing automatically, you will be able to express yourself more musically. Conventionally, when automatic performance is performed using a sequencer or the like, the tempo is expressed by inputting data in advance.

(C) Problems to be Solved by the Invention However, conventional sequencers and the like cannot flexibly change the tempo in real time. This means that the sequencer is nearly incompetent at synchronizing the performance with a human, and the human performer must adapt to the machine. Therefore, in order to solve this problem, a method can be considered in which the tempo clock information generated within the sequencer is supplied externally and the tempo clock information is controlled in real time. Tamping is the most basic means of expressing tempo; that is, the performer taps to generate a tempo clock based on the tapping. Therefore,
Let's consider how to control the computer's performance based on the tempo given by tapping.

First, let's assume that the computer (an electronic musical instrument that performs automatically, such as a sequencer) advances the performance while giving tempos one after another by tapping. In Figure 5, the tap operator (
Suppose that the player (or performer) makes the first tap at position A. At this time, the computer score time and the physical time at the time of tamping are well synchronized. If the performance continues at the current tempo, the next strong beat point (that is, the position to be tapped next) will be at B. At this time, assume that the operator taps at B' a little early to speed up the tempo. Here, there is a difference in musical score time between the operator and the computer (in this case, one-quarter beat).
. Of course, differences in tempo also occur at this time. Therefore, it becomes necessary to match the tempo in order to synchronize the performance of the computer with the performance intended by the operator. In this example, the tempo would be increased by 4/3. However, if that is the case, the computer's next strong beat point will be C, and the operator's tamp will be C', so there will be a time lag (1/4 beat).
will be saved, resulting in incomplete synchronization. Therefore,
It is necessary to eliminate the time lag that occurred when tapping B' in some way. The simplest method is to force the music score time on the computer, which is still at three-quarters of a beat when B' arrives, to one beat. Similarly, at the position of C', the musical score time indicated by C is forced to match the digit 1 of C'.

Figure 6 illustrates this method. According to this, it is possible to completely synchronize the performance of the operator and the computer beat by beat. However, there is one problem with this. In other words,
When the tap is made on B', the computer is still at the 3/4 beat position, so if it suddenly moves to 1 beat, it will be at the 3/4 beat position.
~A note of one beat will sound at that moment. Of course, if there are no notes in between, there will be no real harm, but if there is a quadruplet, for example, those notes will become one degree, which will cause a musical problem.

The definition of physical time and musical score time is as follows.

Physical time: normal time. Refers to time, e.g., in milliseconds, generated by a computer timer.

Musical score time...Represents the position in the musical score. Usually a fraction of one beat is used as the basic unit. For example, as shown throughout this specification, musical score time can be expressed in units of 1/384th of one beat, and M r
According to the DI standard, F8 is interpreted as a unit representing musical score time of 1/24th of one beat.

If we express the system in Figures 5 and 6 using this music score time and physical time, we can express the system in Figures 7 (A), (B), Figure 8 (A), (
B). Here, as shown throughout this specification, musical score time is expressed in units of 1/384th of one beat. This shows that it has been slightly sped up. In this case, the tempo will be slightly faster from the next time onwards, but at t3 the tempo will be 14 (
384-370) If there is a musical score time delay of a unit minute (clock minute) and the tempo does not change thereafter, that delay (time shift) will be preserved as is. On the other hand, the 8th
In Figures (A) and (B), if the tap is struck early at time L3, the third beat musical score time (1152 musical score time position) and t3 will be aligned at that point. Therefore, at this point, 3
Notes equivalent to 14 clocks immediately before the beat are generated at once. The same applies to the fourth tap position.

As described above, simply correcting the tempo or forcibly correcting the time lag has the disadvantage that the performance and the tapping may not be synchronized or the notes may be output all at once, resulting in musical problems.

An object of the present invention is to provide a tempo controller that allows the performance to follow smoothly when tapping by using a certain function to eliminate the time difference (displacement) in musical score time that occurs when tapping.

(d) Means for Solving the Problem The invention according to claim (1) comprises: a tapping means for forming tap data; a musical score time deviation I detection means for determining the amount of musical score time deviation at tap and tap; and the musical score. Musical score time updating means for updating the current musical score time while reducing the amount of time deviation based on a predetermined function; and tempo clock information output means for outputting tempo clock information each time the musical score time is updated. It is characterized by

Further, the description according to claim (2) is characterized in that the method includes means for setting parameters of the function.

Furthermore, the invention according to claim (3) is provided with a tempo deviation amount detection means for determining a tempo deviation amount at the time of tapping, and the score time updating means calculates the score time deviation amount and the tempo deviation amount based on a predetermined function. The feature is that the current score time is updated while decreasing it.

(e) Effect In the invention according to claim (1), when a tap is applied by the tapping means, the amount of deviation between the physical time and the musical score time is determined. Then, the current score time is updated so that this score time shift amount decreases based on a predetermined function. The tempo clock information output means outputs tempo clock information to the outside every time the musical score time is updated. A computer such as a sequencer outputs performance data based on this tempo clock.

The invention according to claim (2) includes means for arbitrarily setting parameters of the function. Trackability can be improved by setting this parameter so that the value returned by the function converges rapidly. Conversely, smoothness can be improved by lowering the convergence of the value returned by the function. The operator can freely set the followability and smoothness of the tray F' off.

In the invention according to claim (3), the amount of tempo shift at the time of tapping is further determined. In the invention according to claim (3), the score time updating means updates the current score time while reducing the tempo shift (2) as well as the score time shift amount based on a predetermined function. The tracking performance is further improved because the tracking is also possible.

(f) Embodiment FIG. 1 shows a professional ivy diagram of an embodiment of the present invention. In the figure, 1 is a tempo controller, 2 is a sequencer, and 3
indicates the sound source, and 4 indicates the sound system. Performance data is stored in the performance data memory in the sequencer 2 in advance. A tempo controller 1 provides tempo clock information to a sequencer 2 via an MIDI cable. Actually, F8 data, not a clock, flows on the MIDI cable. In addition to F8 data,
FA data is output when starting, and FC data is output when stopping. When the sequencer 2 receives the F8 data, it advances the pointer in the performance data memory by one.

That is, the sequencer 2 reads performance data from the internal performance data memory and sends it to the sound source 3 based on this tempo clock. The sound source 3 reads waveform data corresponding to the performance data from the sound source memory and outputs it to the sound system 4.

The tempo controller 1 is a microcomputer 10
．． It is equipped with an i-operation panel 11, a timer 12, a tap switch 13, and an MID I interface 14.

The operation panel 11 includes a start/stop switch, an input switch for an initial time difference elimination ratio (bypassRatio), and an input switch for a tempo difference elimination amount (incTemp o). Timer 12 is used as an external interrupt timer.

Tap switch 13 is a normal on/off switch.

In order to facilitate tamping by the operator, it is desirable that this switch be turned on and off by the up and down movement of the top of the foot, or turned on and off by the up and down movement of the hand. M
The IDI interface 14 inputs F8 data for performance data memory count-up to MrDI based on the tempo clock information output from the microcomputer 10.
Put it on cable 15. Note that the tempo clock information is 0.
When it is 0, no F8 data is formed, the MIDI cable 15 is a MIDI interface 1-0, and the sequencer 2 includes a sequencer main body 20 and a MIDI interface 21. M I D I cable 15 is M
Connected to the MID I IN terminal of I D I Ink 7 S2 1. The sequencer main body 20 has previously stored performance data as shown in the performance data memory provided therein. The number of F8s between event data in the figure is equal to the number corresponding to event intervals on the musical score. The event data consists of, for example, ○N (/-tt7), KCD (pitch), and vEL (key velocity pitch), and when the pointer points to KON, these performance data are sequentially output to note #3. .

With the above configuration, if the period of the F8 data output from the tempo controller 1 becomes short, the sequencer 2 will output performance data such that the musical score time becomes short. Performance data is output so that the time becomes longer.

Next, the operation of the tempo controller 1 will be explained with reference to FIGS. 2(A) to 2(F).

FIG. 2(A) shows the operation when the tap switch 13 is operated. In this flow, the tempo deviation and musical score time deviation are determined, and an operation is performed to eliminate a part of the musical score time deviation.

First, at nl, the musical score time of the strong beat point intended by the operator at the time of tapping is estimated. This position is Guess
It is expressed as Pos. In FIG. 3, if the tap time is t3, this GuessPos is at position 1152 in musical score time. GuessPos is calculated by: GuessPos=(CurPos/Beat)*Beat. Here, Beat is the musical score time of one beat, that is, 384, and CurPos is 0 representing the current musical score time position.For example, if the current physical time is L3 in Fig. 3, CurPos is 384.
s is 1056. Also, (CurPos/Beat
) returns a rounded value. Therefore, for example, if the current physical time is t3, CutPos is 960 to 115.
If the Curios is between 2 and 2, the GuessPos will be 1152, and if the Curios is between 768 and 959, the CruessPos will be 768. In this embodiment, the tempo deviation is also resolved in addition to the musical score time deviation. Therefore, in the next step n2, the tempo is calculated.

Calculation of tempo is: newTempo= (GuessPos-PrevPos)/(CurTi
me-PrevTime). Here, n
ewTempo is the performance tempo to be performed from now on, and P
revPos indicates the previous musical score time position, CurTi
me indicates the current physical time, and PrevTime indicates the previous physical time. In other words, newTempO represents nothing but the slope of a straight line, as is clear from FIG.

Next, the tempo shift is calculated (n3). The tempo difference is tempoDif f=newTemp.

-CurTemp.

It is expressed as

Further, in n4, the musical score time shift is determined.

The music score time difference 1PosDiff is obtained as Po5Diff=CurPos-GuessPos. In the example shown in Figure 3, Po5Diff is -
It is 96. Next, update the data.

That is, GuessPos is updated as PrevPos, and CurTime is updated as PrevTime.

After performing the above processing, a time lag initial elimination module is executed at n6.

FIG. 2(B) shows a flowchart of the time lag initial elimination module. Here, the amount of time difference that occurs during tapping that can be immediately resolved is determined. The coefficient required at this time is the time lag cancellation rate bypassRatio. This bypassRatio is manually set in advance from the operation panel 11 as shown in FIG. 2(C). bypa
The size of ssRatio is set in a range of 0 to 1.

In the time lag cancellation module nlQ, the time lag is set to 1
) CurPos is changed as follows by canceling ypassRatio.

CutPos+= PosDiff*bypassRati.

Note that the above equations are expressed using the C language description method. Expressed mathematically, it is as follows.

CurPos=CurPos -i-PosDi　f　f*bypassRat　i.

In Fig. 4(A), CurP is
It can be seen that os has moved from pl to p2.

Next, the time shift is updated at nil. That is, Po5Diff*= (1-bypassRaLio) You can update it with .

FIG. 2(D) is a flowchart that is executed by a timer interrupt every Mmsec. In this flow, after Tough Bus Inch is turned on, the time and tempo deviations are gradually resolved.

At n30, it is determined whether tempoDiff is O or not. If uempoDiff is O, that is, if there is no tempo deviation, the process advances to n32, where a step for eliminating the time difference is executed. Further, if LempoDiff is not 0, a tempo shift elimination step is executed at n3i, and then a time shift elimination step is executed. The time lag elimination step n32 is performed using the following equation.

CurPos = Po5Diff*0.06; Po5Diff*=0.94 Here, 0.06 is the rate of time lag elimination after the tamping time, and is predetermined. According to this formula, as shown in Figure 4, the first execution results in CurPos being transferred from p2 to p3.
moves. Then, POsDiff is also updated to prepare for the next interrupt.

Further, in the tempo deviation eliminating step of n31, the following equation is executed.

CurTempo+=incTempo ; tempo
Dif f-=incTemp.

Here, incTempo indicates the amount of tempo deviation removed per time, and is input in advance from the operation panel 11 as shown in FIG. 2(E).

FIG. 4(B) shows the above tempo deviation elimination step (n31)
It is transitioned by <CurTemp.

It shows.

As shown in FIGS. 4(A) and 4(B), the amount of musical score time deviation decreases exponentially between taps, and the tempo deviation amount decreases linearly.

FIG. 2(F) is a flowchart executed by a timer interrupt every Nm5ec. In this flow, M
MIDI data F8 for counting up the performance data memory is output to the IDI cable.

n51. n52 maintains physical time and musical score time, respectively. Next was the n53, and the current MIDIC
Find the number of 1ocks. Here, the MIDIC1ock number is the count number at the resolution defined by the MID I standard (the number of counts per beat is 24). Number of MID I Cl o ck to date urF8Cou
nt, is calculated by the following formula: CurF8Count= Cur Pos / F F3 Time
Here, F3Time represents the musical score time per one MIDIC.

Next, in step n54, the number of ki I D I C1oc k to be output to the M I D I cable, that is, the number of F8 data is determined. This is determined by (CurF8Count - PrevF8Count). Here, PrevF8Count represents the previous MID ICloc count. In addition, if this interrupt flow is performed every 3ms e c, for example, the output from n54 ~1lDIC1
The number of ocks (F8 data) is either 0 or 1, and in normal music score performance, there are quite a lot of 0s, and it is thought that it will occasionally be 1.

Next, at n55, PrevF8Count=CurF8CountL is executed to prepare for the next process, and the process returns.

By the above operation, the time lag initial elimination rate (bypass
If you set a large value (Ratio), the automatic performance output will follow the tapping better, and conversely, if you set the value low (Ratio), the smoothness will improve.The operator should make a trade-off between smoothness and followability. It can be selected arbitrarily.Furthermore, in the above embodiment, since the tempo deviation is also resolved, the above-mentioned followability is further improved.

Note that, as shown in FIG. 4(A), the amount of deviation in musical score time is canceled out exponentially, but of course it is also possible to cancel it out using a -order function. Similarly, the amount of tempo deviation can be reduced by any function.
), the time lag cancellation rate is set to a constant value of 0.06, but this value can also be set arbitrarily by the operator.

(g) Effects of the Invention According to the present invention, the automatic performance output when tapping is performed smoothly follows the operator's tapping. In addition, since the parameters of the function that determines the reduction rate of the musical score time lag ■ can be determined by the operator, the operator can further improve the smoothness described above.
Alternatively, it is possible to arbitrarily set the characteristics of followability and smooth time change according to the song, such as improving followability. For example, if you want good followability of a song, you increase the initial cancellation rate that eliminates the amount of deviation immediately upon tapping, and if you want smoothness, you conversely decrease the initial cancellation rate. This makes it possible to realize an optimal temporal change in performance output that follows the taps for each song.

A configuration diagram when connected, FIGS. 2(A) to (F) are flowcharts showing the operation of the tempo controller, FIG. 3 is a diagram for explaining the operation of the tempo controller, and FIGS. 4(A), ( B) is a diagram for explaining changes in the musical score time shift amount and tempo shift l, and FIGS. 5 to 8 are diagrams for explaining the principle of a conventional tempo controller.

1-tempo controller, 2-sequencer, 3-sound source,
4-Sound system.

Claims (3)

[Claims] (1) A tapping means for forming tap data, a score time shift amount detection means for determining a score time shift amount at the time of tapping, and an update of the current score time while decreasing the score time shift amount based on a predetermined function. A tempo controller comprising: musical score time updating means for updating the musical score time; and tempo clock information output means for outputting tempo clock information in accordance with the updating of the musical score time. (2) The tempo controller according to claim (1), further comprising means for setting parameters of the function. (3) In claim (1), further comprising a tempo deviation amount detection means for determining a tempo deviation amount at the time of tapping, and the score time updating means calculates the score time deviation amount and the tempo deviation amount based on a predetermined function. A tempo controller that updates the current score time while decreasing it.