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#26 2010-08-20 21:25:03

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

I thought that I had made clear in my earliest posts and in answer to Tairaku that while bore diameter itself does not affect pitch, those two kinds of end correction can and do. Sorry if that was a mistaken assumption.

I've just read an interesting essay on the difference between explicit and implicit learning. In the first, you are given detailed instruction as to how something works and why, and you flesh that out by practical experiment and trial, in order to match the practice with the theory, so to speak. Implicit learning involves practice in order to reach towards an objective, without knowing exactly how--just by "feel" more or less. Both are valid and effective approaches; the problem is that they use different pathways in the brain, and are not always easy to combine. So I do understand why this stuff gives some of you a headache ;-)

Toby

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#27 2010-08-20 22:06:42

Moran from Planet X
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From: Here to There
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Posts: 1524
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Re: Common tuning errors

Toby wrote:

I thought that I had made clear in my earliest posts and in answer to Tairaku that while bore diameter itself does not affect pitch, those two kinds of end correction can and do. Sorry if that was a mistaken assumption.

I've just read an interesting essay on the difference between explicit and implicit learning. In the first, you are given detailed instruction as to how something works and why, and you flesh that out by practical experiment and trial, in order to match the practice with the theory, so to speak. Implicit learning involves practice in order to reach towards an objective, without knowing exactly how--just by "feel" more or less. Both are valid and effective approaches; the problem is that they use different pathways in the brain, and are not always easy to combine. So I do understand why this stuff gives some of you a headache ;-)

Toby

Do they have a 12-Step Program for slide-rule addiction?

Pass the Excedrin, please.


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#28 2010-08-20 22:33:45

jaybeemusic
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From: Moncton, New Brunswick, Canada
Registered: 2006-06-22
Posts: 145

Re: Common tuning errors

I'm not trying to play the devil's advocate here and with all due respect to all of the Masters out there....but...Just because you've observed something numerous times...doesn't mean that you've deduced the correct "reason" for the observation.  Just because a larger bore flute is lower pitched...doesn't mean that it's "definitely" the bore causing it.....I'm not trying to say anybody is wrong OR right...but consider this....

Imagine the battery keeps going dead in your car...so you replace the battery because it's a "obviously" a bad battery.  sounds logical.  Only thing is that you're wrong, what is "really" going on is that you have a short in the electrical system that drains the battery.  Cause and effect are not always obvious.  I've learned that lesson more than once.

Once again...i'm still a novice player/maker so please understand i mean no offense, and in all honesty, i've observed the same thing as Brian and Ken, but.....I'm just trying to see both sides of the coin.

Jacques


It's better to keep your mouth closed and let people "think" that you're stupid, than to open it, and remove all doubt.

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#29 2010-08-20 22:57:19

Tairaku 太楽
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From: Tasmania
Registered: 2005-10-07
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Re: Common tuning errors

jaybeemusic wrote:

I'm not trying to play the devil's advocate here and with all due respect to all of the Masters out there....but...Just because you've observed something numerous times...doesn't mean that you've deduced the correct "reason" for the observation.  Just because a larger bore flute is lower pitched...doesn't mean that it's "definitely" the bore causing it.....I'm not trying to say anybody is wrong OR right...but consider this....

Imagine the battery keeps going dead in your car...so you replace the battery because it's a "obviously" a bad battery.  sounds logical.  Only thing is that you're wrong, what is "really" going on is that you have a short in the electrical system that drains the battery.  Cause and effect are not always obvious.  I've learned that lesson more than once.

Once again...i'm still a novice player/maker so please understand i mean no offense, and in all honesty, i've observed the same thing as Brian and Ken, but.....I'm just trying to see both sides of the coin.

Jacques

I'm open minded, and in fact it would suit my purposes if what Toby says is true. Ken get to work on a groovy Taimu that plays on Bb for me that fits this theory! I need a Bb instrument. My student took that other one I had.


'Progress means simplifying, not complicating' : Bruno Munari

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#30 2010-08-21 01:42:11

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

jaybeemusic wrote:

I'm not trying to play the devil's advocate here and with all due respect to all of the Masters out there....but...Just because you've observed something numerous times...doesn't mean that you've deduced the correct "reason" for the observation.  Just because a larger bore flute is lower pitched...doesn't mean that it's "definitely" the bore causing it.....I'm not trying to say anybody is wrong OR right...but consider this....

Imagine the battery keeps going dead in your car...so you replace the battery because it's a "obviously" a bad battery.  sounds logical.  Only thing is that you're wrong, what is "really" going on is that you have a short in the electrical system that drains the battery.  Cause and effect are not always obvious.  I've learned that lesson more than once.

Once again...i'm still a novice player/maker so please understand i mean no offense, and in all honesty, i've observed the same thing as Brian and Ken, but.....I'm just trying to see both sides of the coin.

Jacques

Well said. There is a relationship between larger bore and lower pitch, but a larger diameter/volume bore is not directly the cause. This is not a trivial distinction, since these are not organ pipes, where each pipe is dedicated to a single note. As soon as we start drilling holes things change, as similar size holes act differently in different sized bores. The math of all this is a nightmare, at least to me, but I think it is important to realize that it is not as simple as larger bore = lower pitch.

To see how this works, in the case of a master acoustician, and the precision with which one can actually deliberately calculate and design an instrument bore, I suggest you have a look at that Benade paper to which I linked. Skim "To meet a clarinet" starting on pg. 27 and "To meet a flute" starting on pg. 43. After seeing that, I hope that you can have a little understanding of the uses of acoustic science.

Toby

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#31 2010-08-21 03:27:39

Tairaku 太楽
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From: Tasmania
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Re: Common tuning errors

Toby, why don't you buy three pieces of PVC or bamboo of different diameter and make three flutes of the same length and report back to us on the pitch? Make the holes the same size and the utaguchi of the same profile. Or anybody or all of us can do that and report. Talking about it is circular.


'Progress means simplifying, not complicating' : Bruno Munari

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#32 2010-08-21 03:55:24

Toby
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From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

Well, the problem, as I explained, is that while the Ro will differ due to differing end corrections, things will get dicey once you drill the holes, since there is an important factor having to do with pitch that is dependent on bore size to hole size. What exactly would be proved by this empirical experiment? That in playing them the pitches will differ? I think we've already established that--all other things being equal--that will be the case. Also, that won't really transfer to shakuhachi, because the bore is not cylindrical, and this affects some things that can affect the pitch, particularly in the kan and dai-kan, having to do with mode stretching.

What, are you still having trouble accepting that the volume of air in the bore does not affect the pitch? Shall I quote some more sources to you, will that help it go down smoothly?

One more thing needs emphasizing: bore size not affecting pitch applies only to straight cylinders or straight cones. Enlarging, say, the top of the bore while keeping the lower part constant will very definitely lower pitch, and more in the second octave than the first.

Toby

Last edited by Toby (2010-08-21 04:20:41)

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#33 2010-08-21 04:13:18

Christopher B.
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From: Berlin, Germany
Registered: 2009-03-17
Posts: 235
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Re: Common tuning errors

This is really a nice topic even for me. So as you know I am a beginner, when I play with a tuner and playing arround by blowing softer or stronger I noticed the pitch go up and down maybe during the different in air speed? Or is it just a bad embrouche/breathing? So I know it is also possible to play quite and soft an be in pitch but that needs a change in embrouche, right?

So my thought is, I am not familar with building shakuhachi, that it have something to do with the speed of the air. Logicaly you speed up the air to reach Kan by making a smaller room between your lips, that is as we know a different in pitch wink

So maybe same thing happend with the flute bore, if the bore is smaller/narrow the air runs with more speed and the pitch is higher. If the bore is larger/wide the air have less speed and the pitch gets lower.

But I really have no idea about building Shakuhachi.

Best,

Last edited by Christopher B. (2010-08-21 04:20:15)


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#34 2010-08-21 08:48:20

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

Christopher B. wrote:

This is really a nice topic even for me. So as you know I am a beginner, when I play with a tuner and playing arround by blowing softer or stronger I noticed the pitch go up and down maybe during the different in air speed? Or is it just a bad embrouche/breathing? So I know it is also possible to play quite and soft an be in pitch but that needs a change in embrouche, right?

So my thought is, I am not familar with building shakuhachi, that it have something to do with the speed of the air. Logicaly you speed up the air to reach Kan by making a smaller room between your lips, that is as we know a different in pitch wink

So maybe same thing happend with the flute bore, if the bore is smaller/narrow the air runs with more speed and the pitch is higher. If the bore is larger/wide the air have less speed and the pitch gets lower.

But I really have no idea about building Shakuhachi.

Best,

Yes indeed, the speed of the air jet does affect the pitch--the harder you blower, the higher the pitch, until the flute overblows to a higher mode-first the octave, and then the twelfth. You are not doing anything wrong, but more experienced players, when this happens, automatically move the lips slightly closer to the utaguchi, which brings the pitch back down. With experience you will be able to blow harder and keep the pitch the same by adjusting your embouchure position. You can practice this by playing long tones and varying the dynamics from pp to ff and back to pp. Work on keeping the pitch the same during the crescendo and diminuendo, or however they call those things in shakuhachi-speak.

Toby

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#35 2010-08-21 10:02:14

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

Here's the result of my empirical experiment, undertaken in response to Tairaku's suggestion. Two pipes, one aluminum with an ID of 11.48mm and one plastic with an ID of 14.03mm were cut to the same length, 301mm. Both were blown across the top without shading the top hole at all. Both were 550 Hz +-3 Hz. I then closed the bottom to make a closed pipe, which has a fundamental an octave lower. It was not possible to get the fundamental with enough clarity to register on my tuner with the thinner pipe, since the length to diameter ratio was too large, however both would overblow to the twelfth clearly. Here there was a slight difference, about 5 Hz, with the thinner pipe generally playing around 845 Hz and the thicker one around 840 Hz. However when the pipes were blown at maximum dynamic, both were at 848 Hz, +-2 Hz. The difference, then was about 10 cents with a "normal" embouchure, but by changing the embouchure it was possible to vary both pipes by about 60 cents and still get a decent tone, so this is not necessarily a good indicator of the actual pitch of the pipes. In any case, they were very close.

The difference in diameter was slightly more than 22%, corresponding to two 1.8 bores of 19mm and 23.2mm diameter in terms of an analogous difference at that size. That is a pretty big difference in diameter for a nominal difference of 10 cents, if that. And the truer measure of pipe resonance (open pipe), which is not affected by blowing speed, showed no significant difference in pitch.

Toby

Last edited by Toby (2010-08-21 10:07:28)

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#36 2010-08-21 11:33:27

Mujitsu
Administrator/Flutemaker
From: San Francisco
Registered: 2005-10-05
Posts: 885
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Re: Common tuning errors

Toby wrote:

I've just read an interesting essay on the difference between explicit and implicit learning.

Bingo!

Toby wrote:

There is a relationship between larger bore and lower pitch, but a larger diameter/volume bore is not directly the cause. ...........The math of all this is a nightmare, at least to me, but I think it is important to realize that it is not as simple as larger bore = lower pitch.

I think we're ultimately on the same page here. With an implicit approach, one is content applying relationships to get results if the math of direct cause is too difficult to apply. Funny thing is, my original understanding of "larger bore = lower pitch" was one of relationship and not direct cause. Wiring!

Different pathways, semantics. Interesting thread.

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#37 2010-08-21 18:53:02

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

I really only wanted to clear up the misperception that a larger bore plays lower because the wave travels more slowly due to more air mass or something. Another common musical misperception, which doesn't apply to us,  is that the cone angle of a conical woodwind somehow changes the pitch--a wider horn plays lower, for instance. It doesn't, but there are the same kind of incidental reasons that it can.

Back to the original question, though--a hole in the bore does lower the pitch. It is as though the bore looks longer to the air column. In a concert flute, for instance, the physical bore length would play C# without tone holes, but actually plays a semitone lower when fully "outfitted".

For those who might be interested, here is John Neptune's schema for the holes:

Bottom hole:     21% of the length of the entire flute, up from the end.
second hole:      31% of the length up from the end.
third hole:         41% of the length up from the end,
fourth hole:       51.5% of the length up...
thumb:             58% of the length up...

Toby

Last edited by Toby (2010-08-21 19:08:04)

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#38 2010-08-22 02:48:45

Justin
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From: Japan
Registered: 2006-08-12
Posts: 540
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Re: Common tuning errors

Toby wrote:

Guys, this is not a theory, it is physics.

lol

Toby you start to sound rather religious.

I don't really want to join this conversation but thought I may briefly offer my perspective. Toby when you say

Toby wrote:

As counterintuitive as it is, the width of the bore has almost nothing to do with the pitch
Toby

this contradicts the experience of all people experienced in playing wide and narrow bored shakuhachi. I think people are stuck on what you said above, but when reading your posts carefully you seem to be saying something like "according to the theories I study, width of the bore does not effect or change the pitch of shakuhachi, so, that and only that can be true. To account for the experience of wide bore shakuhachi being lower pitch than narrow bore shakuhachi, the theory stays the same but we have to add complications to it and special names and so on, such as "end correction" or even to say

Toby wrote:

A fat flute is effectively more meri than an thinner flute using a normal embouchure.

"

However Toby, that is quite a strange claim because there is nothing yet to suggest that all these players are switching to a deeper meri position when they play wider bore shakuhachi. And, this certinaly could not account for Brian slapping the end of the shakuhachi and getting lower notes on wider bores. hand don't have meri/kari!

I think the people on this forum mostly are taking the experiential approach. They play a whole load of different bore sized shakuhachi, and find a consistent trend that wider bores produce lower pitch. This is not in contradiction to the scientific method. So their conclusion that wider bore give lower pitch is in fact quite scientific, even if it contradicts your theory.

I really encourage you to look into Goethean science. Johann Wolfgang von Goethe worked with (/developed) a scientific method which counted experience as primary, and did not attempt to understand things by explaining what is "behind" them, as the common scientific method does. He did not subscribe to the common scientific view that the "laws" and "rules", ultimately described in the language of mathematics, are "more real" than the phenomena themselves as experienced. (This view is actually based Plato's theory on the separation of the realm of Form and the realm of Ideas, the philosophical foundation of today's "modern science"). Goethe believed that the phenomena themselves are primary and wanted to understand them "from their own side". His method was experiential, and subjective. And yet it was rigorously scientific. This is what we now describe as a "holistic science". I believe this is far more suitable for artists. Indeed far more healthy in general, and by the way in great conformity to Buddhism, in its practice and method.

In the meantime I suggest that people's direct experience, in this case of shakuhachi, can be at least if not more valid than theories and equations. That is not to say that theories and equations are of no use. In the end theories and equations can be useful to apply, for manipulation and control  of phenomena. Indeed that is their primary function, and the reason why modern science is popular in today's world and seen as successful - for it's success in manipulating and controlling nature. However as most people here may be more focused on experience, sometimes I wonder if the scientific language may be not always the most appropriate. On the other hand I think holistic science based on experience and a subjective relationship with phenomena can bring a much deeper satisfaction, and a far deeper relationship to the phenomena being studied. To know something from its own side can be very moving, and is by its nature very personal. We could say this involves not only ones head by largely ones heart. Perhaps a well suited approach to a Zen Buddhist instrument!

Last edited by Justin (2010-08-22 02:56:47)

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#39 2010-08-22 09:19:49

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

I can only repeat what I said, and hope once again that it is clear. The frequency of a standing wave in a tube--all other things being equal--is determined by the length and the speed of sound in the medium of the tube. There is a small difference due to end correction, which is 0.3*tube diameter. This translates to ~6mm for a shakuhachi with a 20mm bore diameter, and ~7.5mm for one with a 25mm diameter. Since shakuhachi do not have cylindrical bores I approximate, but you can see that speaking in terms of physics, which specifically applies to the phenomenal, existential world in which the shakuhachi exists, an increase of 25% in bore diameter in a 1.8 only adds an effective 1.5mm extra length to the bore. This translates into a difference of 4.66 cents for a bore that is much too wide to even play decently on a 1.8. That is not very much at all, is it?

(As far as tapping the ends of the tubes goes: I neglected to mention that in my two tubes of 301mm and 22% bore difference, there may be a minor difference, but it is not more than a few cents, which is what the formula predicts. I wonder if Tairaku's tubes are constant diameter. If not, the answer could well be found there, since any change in bore diameter within the tube will very definitely affect the resonances. And in which case you should tap both ends of the tube. If there is any difference, the bore is not of constant diameter.)

And again, I do not deny that a larger-bore shakuhachi plays lower than a narrower-bore shakuhachi. How many times do I have to say this?? The answer is very simple, and it has to do with the same acoustic principle that allows us to play meri and kari, and get a vibrato without changing air speed, or for a panpipe player to get half steps on a set of whole step pipes. It is, simply put, that the more of the embouchure hole that is covered, the lower the entire pipe will play. I did not mean that one actually plays more meri on a large-bore flute, but--once again as I wrote--the larger the *proportion* of the area of the top hole that is covered as compared to the full area of the hole, the lower the pitch will be, and very much so in some cases.

Clearly, if you come down out of your no-mind Zen meditative stance, you will see that to maintain the same embouchure for a large-bore flute--meaning the same lip aperture-to-utaguchi distance--you are going to have to cover a larger proportion of the end hole. Violà! There is the reason that your large-bore flute plays flatter when you use the same embouchure. I said this in one of my first posts on the subject, but apparently nobody is reading.

I find the whole art vs. science debate not only silly but ultimately destructive. There is no "versus" here: these two aspects of existence complement each other perfectly if you let them--they are not antagonistic, they are synergetic. I never advocate trying to make a flute simply by numbers. That would be silly, as there are too many factors in play for analysis to work beyond a first approximation. Equally silly, though, is rejecting valuable knowledge and fumbling along in the dark using the excuse that feeling is the only way to arrive at the goal. If we were just feeling creatures, without the capacity to think logically, we would still be swinging from trees, and no flutes would exist at all.

It is interesting for me: I discuss musical acoustics in several forums. Generally the sax players, who are very hang loose and don't think that their instruments are spiritual and somehow immune to the laws of physics, have no problems with these concepts, apart from perhaps not having a good grounding in math and science. It is always the flute players, and specifically shakuhachi players, who rail against the notion that their esoteric instruments are really so mundane as to be bound by physical laws.  Exceptionalism is always a curse in the end...

A great acoustic scientist by the name of John Coltman did an experiment some thirty years ago, in which he constructed three pseudo-flutes out of different materials, and invited a number of professional players to try them and comment on them. Almost without fail, each could discern clear differences between them. Coltman then mounted all three on a spindle in the dark, removing all visual and tactile clues, and asked people to play one, rotate the spindle, and find the same one again by sound. Not a single player could do so.

In a later comment to a critic, Coltman wrote this:

"...the musician cannot, under normal playing circumstances, dissociate his personal preferences and prejudices form the question at hand. In the case of the three 'flutes' I constructed, nearly every player who picked them up and tried them had a preference for one or the other. Often he would describe his impressions - the wooden flute has a 'fuller' tone, the silver one 'projects' much better, etc. He was then usually baffled to find that he could not identify any of the instruments under the 'blindfold' conditions I described. The plain facts are that his judgment is influenced by preconceived notions and mental associations of tone quality with other properties of the material. This is a normal human reaction, intensified in the case of those trained to incorporate feeling into their art, and to whom the instrument becomes, in effect, an extension of their own body and personality. I do not belittle this attitude; it is, I believe, a desirable condition for the achievement of the fullest artistic expression. It is just not suited for answering narrow, objective questions like the one I posed - namely: can the material of which a flute is made directly influence the tone quality produced?"

I agree that one must, at some point in the process, allow the heart to guide the head, but the more understanding the head has, the more fully it can cooperate with the heart in achieving their common goal. Only if your head fights your heart at every step, is it necessary or valuable to disempower it.

As far as an apt approach to a Zen Buddhist instrument goes, I could also suggest that perhaps a loss of illusion and a bell-like clarity of perception is also suited to the spirit of the practice.

"One moon shows in every pool, in every pool the one moon."

Toby

Last edited by Toby (2010-08-22 10:14:05)

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#40 2010-08-22 16:01:03

Matt Lyon
Member
From: North Eastern Oregon
Registered: 2009-06-30
Posts: 92

Re: Common tuning errors

Toby,

I think I am getting what you are saying but just to clarify it a bit for me.

Is this statement true: The aspect ratio of the shakuhachi has no real bearing on the pitch. The resulting lower or higher pitch is a result of having the blowing end covered to varying degrees. The aspect ratio and other factors that lower the pitch when a flute gets wider occur as part of the making process to get a playable instrument.

Thanks,

Matt

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#41 2010-08-22 17:41:17

Karmajampa
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From: Aotearoa (NZ)
Registered: 2006-02-12
Posts: 574
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Re: Common tuning errors

Go Toby, I for one appreciate your input, enjoy it even.
My Math teacher would ask, "Are'nt you listening ?" I often replied, "Sir, I am listening, I simply have yet to understand."

However, along the way the parts begin to blend into the whole, and the whole is such a Snark.

I think the variable shape of the bore plays the rascal.

Also, aspect ratio plays a role in tone rather than pitch.

p.s. The part of the flute that is my body is never in the same place twice.

K.


Kia Kaha !

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#42 2010-08-22 20:04:29

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

Matt Lyon wrote:

Toby,

I think I am getting what you are saying but just to clarify it a bit for me.

Is this statement true: The aspect ratio of the shakuhachi has no real bearing on the pitch. The resulting lower or higher pitch is a result of having the blowing end covered to varying degrees. The aspect ratio and other factors that lower the pitch when a flute gets wider occur as part of the making process to get a playable instrument.

Thanks,

Matt

Yes, that's really close. Leaving aside for a moment the intonational flattening caused by covering more of the whole, it is important to note that the fact that the aspect ratio does not affect the resonances (and hence the pitch) of an open tube holds true ONLY if the tube is cylindrical, or--if there is a taper--that the taper remains the same. The important aspect for the tube resonances is the tube profile, not the tube width. Of course as we have seen at great pain, the tube resonances are also affected by what happens at the blowing end, which affects them and thus affects final pitch, but fundamentally, the resonances of the tube are the thing that we want to consider in designing or understanding the characteristics of the bore.

So what does this have to do with the price of eggs as discussed in this thread? Well, my main point was that the reason that the pitch of the flute drops as you add holes is not that you make the bore wider, but that you--effectively--make it longer. All cylindrical instruments propagate plane waves. These travel happily down the bore at the speed of sound--no matter how wide the bore--unless they hit a disturbance. A closed finger hole adds an extra compliance, in scientific terms: When a plane wave hits a hole it is slowed down, because it takes some time for the pressure wave to compress the extra air in the hole. So the timing of the wave is retarded as it climbs in and out of the hole. This lowers pitch. But as long as the bore is straight, the wave just travels along its merry way...

What complicates things in our case is the fact that the bore of a shakuhachi--even without holes--is not straight. It has a reverse taper. A reverse taper bore does not have the big effects of a positive taper (like a sax or an oboe) but it does, among other things, flatten the lower resonances of the pipe.

So if we have two different bamboo pieces to be made into shakuhachi of the same length, and one has a wider bore than the other--BUT the bottom hole and profie at the bottom end are more or less the same (since we generally drill this out in a root-end instrument)--the wider-bore bamboo will have lower resonances than the narrower-bore piece when tapped with the hand.

So why make the bore with a taper in the first place? There is an important reason--to keep the kan and dai-kan from going flat. Why would they go flat? Consider this: as you play higher, you need to make the air jet shorter, which means a subtle adjustment of the lip aperture, moving it closer to the utaguchi edge. You can also do this by blowing harder--and you do--but air speed is a second-order function and jet length is a first-order function. That means that to overblow to the kan and dai-kan without changing the jet length, you have to blow four times as hard for each, which makes the sound not only loud but rough. Overblowing without moving your lips forward is like involuntari kari.

But moving your lips forward shades more of the embouchure hole at the top and flattens the pitch. What's a mother to do? Simple, make you flute with a reverse-taper to lower the otsu as compared to the higher resonance modes of the kan and dai-kan. Then when you play higher the extra shading of the top hole brings the pitch into line with that of the bottom otsu register.

Players don't want or need to know this, of course. All they want is a flute which feels good and lets them play beautifully without getting in the way. But perhaps makers might find this fact interesting.

An analogous story from the dreary and mundane world of Western orchestral instruments. The flute used before the 20th century was shaped more or less like a shakuhachi. It has a cylinder at the top, and a reverse taper in the body. When Boehm invented the modern flute, he wanted to make the body cylindrical, but suddenly the upper registers were flat. He did a very clever thing, he made the top of the flute flare slightly, being contracted at the blowing hole and widening out to meet the cylindrical body tube. This had the reverse effect--it sharpened the upper modes, and he found a curve that exactly worked to compensate for the flattening caused by the player shortening the air jet in the higher notes and making the flute play flatter. So now players could play very naturally, without having to compensate for the acoustic laws of physics as they played. So this is the opposite approach: instead of flattening the lower mode, you sharpen the higher modes. This works the same for players but not for builders, who now need to make the length of the two different kinds of flute different and place the holes differently.

The point is, you take any ideal shape for a musical instrument, and it gets totally messed up by the dirty facts of physical life. In a sax you have to cut off the top of the cone to put a mouthpiece there, and that knocks all the resonances for a loop. Violin and guitar strings have mass and stiffness, so they don't behave properly. With shakuhachi we have side holes and end corrections (among other things). Knowing how things work can help us as builders to make better instruments, or help us tweak ones that are already made. I'm not arguing against feeling (which employs these understandings implicitly, and is a lot quicker than doing all the sums), or tradition (which contains a wealth of this implicit knowledge gleaned over ages encoded within it). But if you have an explicit understanding of these things, you teach a new trick to your pony ;-)

Last edited by Toby (2010-08-22 20:13:33)

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#43 2010-08-22 20:14:46

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

Karmajampa wrote:

Go Toby, I for one appreciate your input, enjoy it even.
My Math teacher would ask, "Are'nt you listening ?" I often replied, "Sir, I am listening, I simply have yet to understand."

However, along the way the parts begin to blend into the whole, and the whole is such a Snark.

I think the variable shape of the bore plays the rascal.

Also, aspect ratio plays a role in tone rather than pitch.

p.s. The part of the flute that is my body is never in the same place twice.

K.

Yes, yes, yes and yes.

Toby

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#44 2010-08-22 20:52:55

jaybeemusic
Member
From: Moncton, New Brunswick, Canada
Registered: 2006-06-22
Posts: 145

Re: Common tuning errors

Ok... so if i understand correctly, the players lips must remain at a constant distance from the Utaguchi for the player to be able to play properly.  Let's say 5mm.  If the bore diameter at the utaguchi is 20mm...that's 25% of the diameter.  or to put it another way....75% of the hole is covered by our chin/lower lip. 

But if the bore diameter is 25 mm...we still must keep the lips at 5mm away from the utaguchi.  and therefore our chin/lower lip is covering MORE (percentage wise) of the hole...about 80%   effectively "shading" the hole more than if the bore was smaller.  like we do with our fingers to lower the pitch.

and since we can't cut off our chin...there's NO WAY that we can play a larger bore flute without shading the hole more.  so no matter what...it's always going to be lower pitched. 

am i correct?

jacques

Last edited by jaybeemusic (2010-08-22 20:55:18)


It's better to keep your mouth closed and let people "think" that you're stupid, than to open it, and remove all doubt.

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#45 2010-08-22 22:26:34

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

Yes, that's exactly right as far as it goes. To take it a step further, being able to reinforce a standing wave in the bore--getting a sound IOW--depends on the jet timing (like the timing of moving your legs on a child's swing keeps it swinging). This timing can be varied in two ways, by changing the speed of the air or by changing the length of the jet. But the effect of these two things is different.

To jump an octave, from otsu to kan, the jet has to be moving twice as fast, but because of physical laws, you need four times the breath pressure to get twice the speed. So you end up blowing pretty hard, and the note gets loud and also unfocused, because of what happens to the shape of the jet when you blow harder. This also tends to de-emphasize the higher harmonics, so the note gets duller as well. This is clearly not ldeal--sort of the sound of a beginner blowing like an idiot to get into kan.

Since length scales directly with jet timing, the other "pure" way to reach kan from otsu is to keep the blowing pressure exactly the same and simply meri until the sound breaks up an octave. Now you have a nice clear kan note, but it is very flat, since you have shaded the hole so much more, and if you blow harder to try to raise the pitch, the flute will tend to overblow into even higher harmonics.

So experienced players learn to unconsciously but finely tune the combination of blowing pressure and jet length, in order to stay in tune, have good timbre (or maximum possibilities of timbre variation) and be able to hold those at a range of dynamics.

It is like riding a unicycle or walking a tightrope: it requires an amazing coordination of lots of different things: blowing pressure, lip opening and position, angle of flute, all seamlessly controlled. Beginners simply can't do it, since the correct neural pathways are not strong enough, and conscious attention is much too slow.

But in any case, yes, a wider-bore flute will always require that more of the hole be covered to keep the same lip-to-utaguchi distance which is critical to the air-jet timing, and this will always cause the flute to play flatter than a narrow-bore flute of the same length and hole spacing.

Last edited by Toby (2010-08-22 22:29:34)

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#46 2010-08-22 23:29:37

Karmajampa
Member
From: Aotearoa (NZ)
Registered: 2006-02-12
Posts: 574
Website

Re: Common tuning errors

Ken could correct or remind me, but I seem to recall , during my visit, you saying you blow Taimu's from a bit further back with your lips ?

K


Kia Kaha !

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#47 2010-08-23 00:06:10

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

There is wiggle room here. In goes in steps. There is quite a range of blowing pressures and distances that will create a standing wave at the first resonance, because the timing of the standing wave locks, to some extent, the jet oscillation into the proper frequency. It is also true that blowing harder will raise the frequency of the whole system somewhat, and blowing softer will lower it, and that it the jet influencing the standing wave into a different frequency from the natural resonance of the tube. The tube resonances are like slots, where it is easiest for the standing wave to develop, but it can be influenced somewhat by various factors (like shading the top hole and jet speed).

But at a certain point, the mismatch is too great, and the so called "regime of oscillation" breaks down. If you are blowing too hard or if the jet length gets too short, a new regime of oscillation will form around the next resonance, which is the octave. Then there is some wiggle room there, but if you continue to blow harder or shorten the jet, it then jumps to the 12th, etc, with the limit being the so called "cutoff frequency" which I will not go into here.

So it is very possible to blow different flutes differently, or the same flute differently, and still get the same note.

Toby

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#48 2010-08-23 00:32:58

Karmajampa
Member
From: Aotearoa (NZ)
Registered: 2006-02-12
Posts: 574
Website

Re: Common tuning errors

This may be a 'curve ball' but I raise my pitch from otsu to kan by tightening my vocal chords, what thinkest ?
Speeds up air column.

K.


Kia Kaha !

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#49 2010-08-23 09:33:21

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Common tuning errors

Methinks that there must be something else going on as well. The air speed is going to be determined by the back pressure and the size of the smallest opening in the air feed system. Think about a dam with outlet works that allow the water to flow through pipes at the bottom. The more the pressure, the faster the water will be pouring through, but simply making a part of the river upstream narrower is not going to increase the water speed flowing through the outlet pipe, since the water is slowed to near zero at the dam itself.

At most, narrowing your throat could increase turbulence at the air jet, but this is neither desirable nor will it make the octave jump. I suspect that at the same time you are narrowing your throat, you are increasing the blowing pressure with your intercostal muscles. The body is hooked up like that--you may think that a smile is just retracting muscles at the corners of your mouth, but actually you are involving up to 53 sets of muscles to varying degrees. I'm guessing that you not only increase pressure, you probably subtly alter your embouchure as well.

Toby

'Everyone is entitled to his own opinion, but not his own facts.'
--Daniel Patrick Moynihan

Last edited by Toby (2010-08-23 09:46:17)

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#50 2010-08-24 13:46:52

Kerry
Member
From: Nashville, TN
Registered: 2005-10-10
Posts: 183

Re: Common tuning errors

Toby wrote:

Methinks that there must be something else going on as well. The air speed is going to be determined by the back pressure

By embouchure alone???


The temple bell stops, but the sound keeps coming out of the flowers. -Basho

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