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Scientific investigations of Stradivarius violins--an updated review article


Bruce Tai
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This thread evolved badly over night (while the fittest were a sleep)

Bruce:

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To me, they seem to be superhumans--Heifetz, Milstein, and Menuhin before WWII. As historical mono recordings become better restored, I am blown away by their performances on the Bach sonatas and partitas. You have to be super sensitive to be that amazing. Is it painful? God bless their souls.

I brought the "super human" here, with Perlman and Wienawski concerto no. 1. There are some still living. Gitlis has passed, he was  super special.

The super super humans are the composer and virtuosos, no living that I'm aware of.

Recently I have studied Zapateado recordings:

- Sarasate original recording

- Perlman

- Midori Goto

It's amazing....

I might continue this...

 

 

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4 hours ago, Bruce Tai said:

image.png.b73ddca11324ddef100796bc471861d5.png

 

A small figure to show what we are doing right now (the Chinese caption is to avoid the problem of revealing data before publication). To the left we are spinning wood powders at world-record 150 kHz for solid-state NMR experiment. That's equivalent to tens of millions of g force. By comparison, the fastest commercial centrifuge in the world is only 1 million g force, made by Hitachi. Are we truly understanding the nanostructure of wood using such fancy instrument? Not even close. 

To the right you will see a top row of modern maples. Then we have three Strad maples from 1725, 1731, and 1717. The French 1750 quinton violin is also shown. You don't need a PhD degree in small angle X-ray scattering to see that the wood has changed a lot. What change is due to aging and what change is due to manipulation, we don't know yet. How do we interpret the X-ray scattering changes in terms of molecular alterations? We have been working on this for several years. This is new territory for science. 

The simplest polymer in wood is cellulose, which are chains of glucose. Hemicellulose and lignin are much more complex. Cellulose is synthesized as mini bundles by enzyme complexes with six-fold rosette symmetry. So the number of chains in each bundle is 6N, multiples of six. Scientists are still debating if the number is 18, 24, or 30. A lot of old textbooks say 36. We can take pictures of blackholes, but we can't count the cellulose chains in wood. Let's just say that wood research is not funded on the same level as the cosmology research. Sort of like a modern violin vs a Strad. We are trying to be the first lab to give a definitive answer on cellulose chain counting in normal woods. 

Even to the untrained eye, it is obvious that modern maples give a cross-shape signals. It's because most wood cellulose fibers are either vertically oriented or horizontally oriented, being perpendicular to each another. Aged maple have become more randomly oriented, giving oval-shape signals. The hemicellulose degraded and the cellulose fibers have room to rearrange. It is hard to imagine why rearranged wood fibers would not lead to altered acoustics. The best players may figure out how to make different sounds because the wood seems to have more flexible and rearranged molecular structures. Hard to prove the case on the sound being produced, but denying such possibilities based on flawed "blind tests" is unwise. Don't let the blind lead the blind. 

Modern maple are basically all the same at the molecular level. At the tissue level no two trees are the same and no two planks are the same. Aged, manipulated maples from Cremona are quite diverse and differ even at the molecular level. It is conceivable that the top players can feel these subtle differences and figure out how to create unique tone palettes using their extraordinary techniques. To me, they seem to be superhumans--Heifetz, Milstein, and Menuhin before WWII. As historical mono recordings become better restored, I am blown away by their performances on the Bach sonatas and partitas. You have to be super sensitive to be that amazing. Is it painful? God bless their souls. 

Thanks for posting this.  I see what you are doing, and applaud your improved methodology.  It looks like you're approaching a quantified description of wood degradation, but will documenting an uncontrollable process to unprecedented levels of accuracy somehow benefit the practical luthiers here, or only thrill the dealers?  :huh:  

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Carl wrote:

"I drove A LOT of miles over some 40 years but I am not a good driver and I would definitely not try educate this one the kind of tools of the trade she should chose. That's because I have no expertise in the matter - by comparison, I am clueless :"

In general, high level pro racing drivers do not choose their "tools of the trade".  They are hired by car companies or racing teams, and drive what their employer or sponsor specifies or furnishes. You can look up who Sabine has worked for.

Certainly, she was a giant at the Nurburgring. living nearby, and probably having made more laps around that racetrack than anyone else, partly because one area of her employment was as a "Nurburgring taxi driver", giving those who could afford it thrill-rides around the racetrack.

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12 hours ago, Carl Stross said:

I drove A LOT of miles over some 40 years but I am not a good driver and I would definitely not try educate this one the kind of tools of the trade she should chose. That's because I have no expertise in the matter - by comparison, I am clueless :

I think she pushes the brakes or let the engine brake just a little early, before the corners. 

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7 hours ago, Bruce Tai said:

To the right you will see a top row of modern maples. Then we have three Strad maples from 1725, 1731, and 1717. The French 1750 quinton violin is also shown. You don't need a PhD degree in small angle X-ray scattering to see that the wood has changed a lot. What change is due to aging and what change is due to manipulation, we don't know yet. How do we interpret the X-ray scattering changes in terms of molecular alterations? We have been working on this for several years. This is new territory for science. 

This is the new territory for more violin pseudoscience. The sample set (n=4) is simply way too small to make any conclusions; you don't need a PhD in statistics to see that. But making big claims from insufficient and unsupportable data is what violin pseudoscience is all about.

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40 minutes ago, GeorgeH said:

This is the new territory for more violin pseudoscience. The sample set (n=4) is simply way too small to make any conclusions; you don't need a PhD in statistics to see that. But making big claims from insufficient and unsupportable data is what violin pseudoscience is all about.

Of course we have measured many flakes from many different boards and different instruments many times, at two different synchrotron facilities. The reader can't possibly handle all the data that we have collected, so we just show the summary resutls.

Have you heard of patient HM (https://en.wikipedia.org/wiki/Henry_Molaison)? He is a special case with special brain damages and special memory deficits. He taught us so much about learning and memory. One of the most amazing N=1 in scientific history. Who says N=1 can't be real science :P The key is to find THE ONE. So when can I get my hands on Paganini's Canon violin to do some analyses?   

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3 hours ago, Violadamore said:

Thanks for posting this.  I see what you are doing, and applaud your improved methodology.  It looks like you're approaching a quantified description of wood degradation, but will documenting an uncontrollable process to unprecedented levels of accuracy somehow benefit the practical luthiers here, or only thrill the dealers?  :huh:  

If we know enough about wood processing and accelerated aging (sadly we don't), we can give modern tonewood the same molecular properties as aged/treated Cremonese wood. I would rather see our academic research benefit the makers than the dealers. But the market never follows the layman's wishes. 

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3 hours ago, David Burgess said:

Carl wrote:

"I drove A LOT of miles over some 40 years but I am not a good driver and I would definitely not try educate this one the kind of tools of the trade she should chose. That's because I have no expertise in the matter - by comparison, I am clueless :"

In general, high level pro racing drivers do not choose their "tools of the trade".  They are hired by car companies or racing teams, and drive what their employer or sponsor specifies or furnishes. You can look up who Sabine has worked for.

Certainly, she was a giant at the Nurburgring. living nearby, and probably having made more laps around that racetrack than anyone else, partly because one area of her employment was as a "Nurburgring taxi driver", giving those who could afford it thrill-rides around the racetrack.

You mean, "who she chose to work for".   It's not like Merc, Nissan, Honda, Toyota etc weren't around. The fact me and her drove at certain times the same BMW models does not cloud my judgement.

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1 hour ago, Anders Buen said:

I think she pushes the brakes or let the engine brake just a little early, before the corners. 

I see. What is "think" ?

The idea that from the comfort of your computer and while lacking any experience you can "tell" what a genius of that caliber does wrong is ... in keeping with things we keep reading on MN. :)   

And Jeff picks on me.....  

 

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4 hours ago, l33tplaya said:

  I hear VdA has a great Strad she can set aside for you. It says so on the label.  With her permission, feel free to check it yourself. Or is this another opinion masquerading as fact? 

 

What are you talking about ????  Get brain in 1st, release clutch gently and read what I actually wrote.

It was a joke.

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27 minutes ago, Bruce Tai said:

Of course we have measured many flakes from many different boards and different instruments many times, at two different synchrotron facilities. The reader can't possibly handle all the data that we have collected, so we just show the summary resutls.

 

Isn't it the job of the researcher to use whatever data analysis/statistical techniques are required in order to enable the reader to "handle all the data that we (you) have collected"?

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4 hours ago, Muswell said:

Did you know that she died last month? The video of her doing the same circuit in a Ford Transit van is a wonder.

Yes. I never met her but some relatives of mine knew her quite well from the hotel business side. 

The van bit was stunning and I understand, also extremely dangerous. Of minor interest, I have a relative who won at Nürburgring and I very much regret he never met her. 

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36 minutes ago, Bodacious Cowboy said:

Isn't it the job of the researcher to use whatever data analysis/statistical techniques are required in order to enable the reader to "handle all the data that we (you) have collected"?

Of course it is. But it is one of the classic excuses of pseudoscience to claim that the data cannot be adequately or properly interpreted by non-believers. And the argument about n=1 science is an absurd smokescreen. Of course, there is n=1 science, but that is not what is useful or at all relevant here. When trying to show 2 groups of similar objects are different using statistical analysis, n=4 non-random samples of indeterminate origin are wholly inadequate. 

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1 hour ago, Carl Stross said:

You mean, "who she chose to work for".   It's not like Merc, Nissan, Honda, Toyota etc weren't around. The fact me and her drove at certain times the same BMW models does not cloud my judgement.

BMW and Porsche do a huge amount of testing there.  The racetrack is almost in their back yard. For other companies, it's a lot less expensive to do more of their testing closer to home. Ford doesn't do any testing there at all. Both GM and Chrysler have major race/testing tracks close to Detroit. How much money do you think Sabine would have made driving the Nurburgring for Ford? :lol:

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14 minutes ago, David Burgess said:

BMW and Porsche do a huge amount of testing there.  The racetrack is almost in their back yard. For other companies, it's a lot less expensive to do more of their testing closer to home. Ford doesn't do any testing there at all. Both GM and Chrysler have major race/testing tracks close to Detroit. How much money do you think Sabine would have made driving the Nurburgring for Ford? :lol:

I have no idea and that's why I didn't mention Ford.  And I don't know if a Ford could complete a lap without a couple of repairs and a full overhaul. And I did own a couple of the faster Fords........  I don't know anybody who drives GM or Chrysler - I'm not living in that sort of a suburb...  :)

I think ( speculate ) that her choice was to some extent sentimental. In the end, VW are the ones who  really through money at these things. 

 

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12 hours ago, Bruce Tai said:

image.png.b73ddca11324ddef100796bc471861d5.png

Even to the untrained eye, it is obvious that modern maples give a cross-shape signals. It's because most wood cellulose fibers are either vertically oriented or horizontally oriented, being perpendicular to each another. Aged maple have become more randomly oriented, giving oval-shape signals. The hemicellulose degraded and the cellulose fibers have room to rearrange. It is hard to imagine why rearranged wood fibers would not lead to altered acoustics. 

Pardon my editing out all the pointless player worship, but now I think we may be getting somewhere.  I don't pretend to understand what we're looking at and how it works, but if you can show a consistent difference related to the internal cellulose/hemicellulose arrangement, I definitely agree it should translate into an acoustic difference.

These plots are for maple... do you have anything for spruce, and if so, what does it show?

4 hours ago, Bruce Tai said:

If we know enough about wood processing and accelerated aging (sadly we don't), we can give modern tonewood the same molecular properties as aged/treated Cremonese wood. I would rather see our academic research benefit the makers than the dealers. But the market never follows the layman's wishes. 

I could send you some of my processed wood offcuts, if that would be of interest.  I do NOT expect them to look like 300 year old violin wood, as I don't see the "old Italian" spectral response in violins made with this wood (IMO just a more lively modern sound).

It is unfortunate that we can't cut up a bunch of Strads and test the wood properties directly, so we'll have to make some educated guesses.  For now, my leading hypothesis has been based on a few observations:

1) The "old Italian sound" is characterized by weakness around the middle frequencies, a "bridge body hill" shifted to lower frequencies, and (my measurements) A0 frequency lower than expected. This to me suggests degradation and loss of stiffness, perhaps mostly in the maple which is more involved in the middle frequencies.

2)  In processing, maple seems to be much more sensitive than spruce, so I have been using a much milder process for maple.  This might infer that age affects maple more than spruce.  

3) In spruce processing, speed of sound and radiation ratio reach a peak, and with stronger processing begin to degrade.  However, damping continues to be reduced as processin is extended.  I haven't tested maple for this effect.

Putting this all together, I'm thinking that old violins have backs that are less stiff, and overall lower damping than you can get with modern wood... even processed wood.  I have not taken this to the logical experiment of heavily processing maple until it gets much weaker, as it would be far too dark to sell easily.  But maybe some day.

Edit:  We have quite a bit of information on old violin top plate taptones, and to my eye it doesn't appear to be anything out of the range of modern wood (damping is unknown) which implies that stiffness has not been degraded.  So if there is stiffness loss, it might just be in the maple.  I haven't seen any back plate taptone data to check this.

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11 minutes ago, Don Noon said:

Pardon my editing out all the pointless player worship, but now I think we may be getting somewhere.  I don't pretend to understand what we're looking at and how it works, but if you can show a consistent difference related to the internal cellulose/hemicellulose arrangement, I definitely agree it should translate into an acoustic difference.

These plots are for maple... do you have anything for spruce, and if so, what does it show?

I could send you some of my processed wood offcuts, if that would be of interest.  I do NOT expect them to look like 300 year old violin wood, as I don't see the "old Italian" spectral response in violins made with this wood (IMO just a more lively modern sound).

It is unfortunate that we can't cut up a bunch of Strads and test the wood properties directly, so we'll have to make some educated guesses.  For now, my leading hypothesis has been based on a few observations:

1) The "old Italian sound" is characterized by weakness around the middle frequencies, a "bridge body hill" shifted to lower frequencies, and (my measurements) A0 frequency lower than expected. This to me suggests degradation and loss of stiffness, perhaps mostly in the maple which is more involved in the middle frequencies.

2)  In processing, maple seems to be much more sensitive than spruce, so I have been using a much milder process for maple.  This might infer that age affects maple more than spruce.  

3) In spruce processing, speed of sound and radiation ratio reach a peak, and with stronger processing begin to degrade.  However, damping continues to be reduced as processin is extended.  I haven't tested maple for this effect.

Putting this all together, I'm thinking that old violins have backs that are less stiff, and overall lower damping than you can get with modern wood... even processed wood.  I have not taken this to the logical experiment of heavily processing maple until it gets much weaker, as it would be far too dark to sell easily.  But maybe some day.

 

Do you think the change in geometry due to sound post stretching/bridge sag have anything to do with it? 

 

Just for laughs, in the heavy metal world amplifiers with 'scooped mids' became popular in the 90s..

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3 hours ago, GeorgeH said:

Of course it is. But it is one of the classic excuses of pseudoscience to claim that the data cannot be adequately or properly interpreted by non-believers. And the argument about n=1 science is an absurd smokescreen. Of course, there is n=1 science, but that is not what is useful or at all relevant here. When trying to show 2 groups of similar objects are different using statistical analysis, n=4 non-random samples of indeterminate origin are wholly inadequate. 

Thanks for your "professional" advice. In return, please show me your published work involving proper statistics and I will give you courteous advices on how to improve the statistical methods being used, free of charge. 

 

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