Chemical distinctions between Stradivari’s maple and modern tonewood

[Bruce Tai]

In another thread, someone mentioned a news article in The Times about our new research. 

The reporter from The Times did a phone interview with me, but it would be more accurate if you simply read our paper directly.

Here is the link to our new paper:

http://www.pnas.org/content/early/2016/12/13/1611253114.full

 

Chimei Museum paid the extra fee for open access option ($1100) to make sure that our friends in the violin community can read the full paper right away.

You can download the PDF+SI to see all our quantitative data on Cremonese woods. 

 

[Don Noon]

Thanks a lot for this, Bruce.  I don't have time right now to read it, but for sure I will soon.

[Violadamore]

*****THANK YOU*****

[Davide Sora]

Thanks so much for sharing.

[jezzupe]

In another thread, someone mentioned a news article in The Times about our new research. 

The reporter from The Times did a phone interview with me, but it would be more accurate if you simply read our paper directly.

Here is the link to our new paper:

http://www.pnas.org/content/early/2016/12/13/1611253114.full

 

Chimei Museum paid the extra fee for open access option ($1100) to make sure that our friends in the violin community can read the full paper right away.

You can download the PDF+SI to see all our quantitative data on Cremonese woods. 

Thanks for making it available, interesting stuff

[Bruce Tai]

Here is a nice article in NY Times summarizing our study:

 

 The Brilliance of a Stradivari Violin Might Rest Within Its Wood

[Scoiattola]

Hi Bruce,

 

Thanks so much! Been looking forward to this paper since I first heard about it.  

 

 

Thanks also to Chimei Foundation for making it possible!

 

Scoiattolo

 

[Don Noon]

Very good paper.  Skipping over a lot of the terminology that might only be understood by an analytical chemist, the one line that I found most important was:

 

"Our findings with respect to cellulose stability, mild lignin oxidation, and significant hemicellulose decomposition in historical maples were in reasonable agreement with the reported effects of dry aging on wood (8)."

 

The "significant hemicellulose decomposition" in turn leads to reduced moisture content, and the lowered hemicellulose and moisture lead to significant reductions in damping (although I don't recall that this latter effect was pointed out in the paper).  There was one reference cited (31) claiming reduction in damping due to vibration for short periods; I don't have that one, and it goes against what I have found to be true... but I don't have the details of what wood, what vibration levels, etc.

 

Another item I found interesting was the listing of the estimated rate of hemicellulose degradation, which happens more than twice as fast in maple compared to spruce.  There is a lot of data on top plates of old violins (weights and taptones), but almost nothing on the back plates.  So it is difficult to find any clues to anything that might be happening to the maple.  I have suspected for a while that something might be going on in the maple, based on perceived response differences from modern instruments in the "transition hill" frequencies, where the back plate is most active.  But that's just speculation at the moment.  As a side note, in hydrothermal processing I have noticed that maple is far more sensitive than spruce, and use a much milder processing for maple.  

 

On the topic of mineral infusions... it looks like a red herring to me regarding tone.  The total weight is not enough to make a big deal in density.  It's not going to do anything to the cellulose, and if it does something to the hemicellulose, you have to ask what it's doing.  From the highlighted line above, we have to conclude that it isn't catalyzing the degradation of hemicellulose, since that looks like it would happen anyway.  If we then postulate that it's crosslinking the hemicellulose into something with greater stiffness and less damping... there's no current proof that it happens, but we've already shown huge reductions in hemicellulose and moisture, which are real and have consequences acoustically.

 

However, mineral infusions may have led to more of such treated instruments surviving the ravages of bugs and fungus attack.  I think I'll be adding a light coating internally to my instruments for this reason, and for future researchers to ponder the odd chemical composition of my instruments.

[Janito]

What about analysis of wood samples from contemporaneous furniture.

 

If the same (similar) chemical signatures are found there, it would cast doubt on the validity that they have anything to do with 'sound', unless one plays musical chairs.

[GeorgeH]

This article provides no evidence that the insecticide treatment has anything to do with violin sound, and the whole article is a bunch of analytical tests on some wood of unproven provenance that proves nothing.

 

There is no objective "Stradivari sound." Every violin has a unique sound; no two individual violins sound identical, including Strads, Guarneris, and the lowliest factory fiddle. Trying to extrapolate these analytical results from (maybe) a few Strads and Guarneris to explain a nonexistent quality of all Strads and Guarneris is absurd.

 

In regards to wood deterioration and/or changing over time, there is no proof offered (and indeed, none is possible) that this improved the sound of the instruments over time. It is more likely that the violins were at their peak when new, and the sound stayed the same or deteriorated over time.

[Bill Yacey]

If the metal salts are found primarily on the surface wood, it would seem to attribute the application to the violin maker.

 

If it's throughout the wood, and similar treatment is found in contemporary furniture wood, it would point towards a treatment common to the wood suppliers. That would be an interesting avenue to follow up on.

[Bill Yacey]

 It is more likely that the violins were at their peak when new, and the sound stayed the same or deteriorated over time.

Empirical evidence has shown that played violins tend to loosen up and mature in an audible manner over time.

[GeorgeH]

Empirical evidence has shown that played violins tend to loosen up and mature in an audible manner over time.

 

Prove it. 

[Don Noon]

In regards to wood deterioration and/or changing over time, there is no proof offered (and indeed, none is possible) that this improved the sound of the instruments over time. It is more likely that the violins were at their peak when new, and the sound stayed the same or deteriorated over time.

 

I think that the study has shown that there are differences in old and modern maple that logically translate to a difference in acoustic properties, and therefore a possible difference in sound.  

 

I do believe that the sound "deteriorates" over long periods of time... but that the part of the sound that deteriorates is stuff most listeners find offensive anyway.  I don't think modern instruments are hurting for dB levels.

 

I too would like to see proven that playing and instrument changes the sound.  At the moment, I'd replace "empirical" with "anecdotal".

[Bill Yacey]

I suppose I should have defined the time periods I had in mind. A fresh (new) instrument from the makers hand up to perhaps 6 month or even a year will undergo changes that usually are viewed as a positive acoustical change. After this period the violin settles in, arriving at a more or less stable plateau that gradually declines over the life of the instrument, (excluding the abrupt effects of physical damage or tampering).

[GeorgeH]

I suppose I should have defined the time periods I had in mind. A fresh (new) instrument from the makers hand up to perhaps 6 month or even a year will undergo changes that usually are viewed as a positive acoustical change. After this period the violin settles in, arriving at a more or less stable plateau that gradually declines over the life of the instrument, (excluding the abrupt effects of physical damage or tampering).

Bill, Thanks for the clarification - this is much more plausible (even testable) than the "violins get better over centuries" dogma.

[GeorgeH]

I think that the study has shown that there are differences in old and modern maple that logically translate to a difference in acoustic properties, and therefore a possible difference in sound.  

 

Don, actually, the paper shows nothing of the sort. The broad conclusion that "In their current state, maples in Stradivari violins have very different chemical properties compared with their modern counterparts, likely due to the combined effects of aging, chemical treatments, and vibrations" is not simply supported by the evidence offered in the paper.

 

It is a paper that is drowning in confirmation bias.

[Violadamore]

Don, actually, the paper shows nothing of the sort. The broad conclusion that "In their current state, maples in Stradivari violins have very different chemical properties compared with their modern counterparts, likely due to the combined effects of aging, chemical treatments, and vibrations" is not simply supported by the evidence offered in the paper.

 

It is a paper that is drowning in confirmation bias.

Had a hard time in upper level chem courses, did you now?    Tai demonstrates via NMR spectroscopy that hemicelluose levels were lower and lignin oxidation levels were higher in historical compared to modern maples, making this obviously related to age.  See his Figures 2 and 3.  He also sorted the historical and modern maples into different groups by inorganic element constituents using mass spectrometry.  See his Figure 6.  He clearly demonstrates that the Strad wood and the control samples differ greatly. 

 

He details where his samples came from.  I find no fault there either.

 

I love the part where he discusses differences between Nag's methodology and his own as well as the differences in findings.

 

The only speculation I find is about the role (if any) played (pun intended) by vibration. 

 

There's nothing in his methodology to argue about.  Why do you have a chip on your shoulder?

[Jacobus Drainer]

You can put what you're saying another way, which is if Strad could get his hands on some wood from the 20th century his violins would come up short.  Be careful...

[tamiya]

Q for any biochemist/chemherbologist?! out there...

Are we certain that all odd chemicals found in the wood is applied only after its felled?

Am think of a tree growing in heavy polluted atmosphere, would it accumulate pollutants into its heartwood?

[David Burgess]

 

 

It is a paper that is drowning in confirmation bias.

Maybe, maybe not. Hard to say at this point. Thanks for bringing up that possibility.

 

And thanks also to those with good scientific or technical backgrounds, who may not see that as an overriding factor.

[Don Noon]

You can put what you're saying another way, which is if Strad could get his hands on some wood from the 20th century his violins would come up short.  Be careful...

 

They would sound "modern".  If you look around, you can find some Strads that come up short (whatever that means).  He was admittedly a good maker, but no supernatural powers.

[Jacobus Drainer]

They would sound "modern". 

I don't know how I would make that determination, but I'm no maker.   I couldn't prove they wouldn't still have the unique or magical Strad sound that the purpose of the paper is to chase?

[David Burgess]

He was admittedly a good maker, but no supernatural powers.

Oh my gawd, hope you've got the weapons in place to protect your home and family from rabid retributive Stradivarites!

[Jacobus Drainer]

So Don, would he make a couple of violins from modern woods, end up throwing them against the wall and start placing orders from the magical forest again?  Somehow I think he could make new wood work.  He might not have to do anything different at all.  Presumed lesser makers reportedly give him a run for his money using modern wood.