A three centuries old mystery: The Secret of Stradivari

It's a favorite media story: The Secret of Stradivari Discovered!   It seems every six months or so for the last hundred years we get a round of stories about the secret of Stradivari.  It's romantic and fun.  Seems it never ends.



And the secret is:

• The little ice age.
• Mushrooms
• Shrimp Shells
• Cheese Glue
• Bent Wires
• Plate Tuning
• Gamboge Resin
• Emulsion Varnish
• Water Soaked Wood
• Iso Line Arching
• Cinnabar Varnish
• Bug Repellent 
• Imperfections 
• Borax 
• Scraping and Pricking Inside the Violin
• Particles in Varnish
• Boiled and Baked Wood
• Sound Hole Shape

This is just a sampling of theories floated around in recent years.  Some are new.  Some have been recycling for decades or even centuries now.  The long standing violin journal The Strad  documents an unending stream of such ideas, some partially credible, most ludicrous.

So is there a secret at all?  Since Stradivari is revered above all others, we naturally look for a simple explanation.  Science and modernization haven't outdone Stradivari.  This in itself is surprising, and makes the violin somewhat unique among objects in active current use.   So we have an impulse to assume some lost arcane secret explains the situation.

If there is a secret, is it Stradivari's alone?   Guarneri Del Gesu didn't have as long a career, or leave us anywhere near as many instruments, yet the best Del Gesu violins are as or more valued by concert soloists.   Did Del Gesu also possess the secret?   But Del Gesu had both older and younger family members whose instruments are highly valued, but not as much as Strad or Del Gesu.   Did the whole family possess the secret?   What about Strad's sons or his apprentice Bergonzi?  And what of the Amati family?  Before the success of Stradivari, their instruments were treasured as the best of all.  And then what about Stainer who may have trained in Cremona, but worked in Absam on the other side of the Alps?  At times and in some places more than others, his instruments were once valued above all others.  Did all these makers possess the secret?

We tend to simplify by glorifying Stradivari only.  But in truth, the whole broad group of Classical Italian makers are highly valued.  In general they are more highly valued than any later group of makers, and more than making traditions from other regions.   Among the Italians, the Cremona makers are valued most, and the best of these have become almost mythological.

The question isn't just what makes Stradivari the best, but also what makes the broader Italian making around him so valued?  The question is all the more interesting since this broader group of makers demonstrates that one can sometimes make a very successful musical instrument, yet fail to achieve Strad's wonderful level of craftsmanship.   In fact, wonderful musical instruments from this treasured group of Italian makers can sometimes show very rough workmanship in some details.

Scroll from ca1744 Del Gesu violin in the Ford Collection

The idea that a few individuals among a group stand out more is unmysterious.  All human endeavor shows this trait.  Stradivari is a standout leader among a larger group of makers that are generally held in esteem above other groups of makers.   We don't need a secret to explain one individual's success exceeding his peers.

Talent is a powerful force.   Is there a secret that causes Bach to stand out among Baroque composers? Or Mozart above his peers?  Or Beethoven above his?   Did they merely possess special secrets that would have produced equal results in other hands?   No.  They didn't possess secret tools, they just used the same tools to better effect.

So if there are secrets, they are most of all secrets of the general Old Italian making, rather than secrets of Stradivari in particular.   And in this sense, it might be more elucidating to first try to understand what makes the less talented Old Italian makers as effective as they are.   Such knowledge would likely shed strong light then on what helps makes Del Gesu or Strad even more special.   Just as a study of Bach would be less effective unless it begins first with understanding the shared common aspects of Baroque music.

So if there are secrets of Old Italian making, what might they be?

Is it the varnish?

Perhaps.  Many have focused on the varnish.   Certainly this is part of the beautiful and complex appearance characteristic of the Old Instruments.  And discussions of violin making secrets, varnish has always been a favorite topic.

Varnish, or more generally the finish of the instrument, can be shown to have effects on the communication of vibrations from the instrument to the air, and it can beneficially or harmful dampen the vibrations of the violin body.   So there is some cause to consider the varnish acoustically significant.

On the other hand, consider that very few old instruments come down to us with their varnish unaltered.   Most have lost varnish on part of their surface.   Most have been polished and repolished countless times with a technique that adds new varnish to the surface.   Many have areas of retouched or added new varnish.    Yet these things are not considered to significantly detract.    Pristine original varnish, while prized for historical value, is not of great consideration for a concert instrument.

Also, there isn't a single old Italian varnish.  Across the various towns and regions, and across the generations comprising Old Italian making, we see much variation in the finishing of instruments.   So we can't very well look to one particular arcane method of finishing to be 'the secret'.

Unfortunately, the science labs haven't even settled the discussion of what's in those old finishes.   Partly this is because samples are hard to get.  Cutting off a chunk of wood and varnish from a treasured antique instrument isn't a popular choice.  Further, tests have limits.  To date, tests tend to have trouble distinguishing between different kinds of organic components like similar oils or resins.  And many tests lose track of the spatial relation between components in a finish.

Some studies have shown layer structure in the classical finishes, others appear to not show layers.   Some studies found particulate content in instrument finishes, others studies concluded not.  Some studies found proteins, some didn't.   Some studies indicate color stains, others not.

It's good to remember that because of limitations of testing methods, 'not found' doesn't necessarily mean 'not there'.   'Found' tends to be more meaningful.  However, because instruments have so much retouch and non-original varnish on them, without proper care a 'found' result might not come from the original finish.

Fluorescent cross section image from a Strad cello
showing both layer structure and particulates 

Is it the wood?

Special wood, or specially processed wood, or aged wood are popular versions of the secret.  Again though, we see a variety of wood choices in these old instruments.  So there can't really be a single simple secret here.

Again, science has not yet provided a detailed enough picture to answer all such questions, but there have been some clarifying results.

From recent studies:

• The wood densities in classical instruments are not significantly different than in modern wood supplies
• The difference in density between the resinous dark bands and the light bands in the wood is less in the old instruments than is common in modern wood sources.
• Dendrochronology shows that some of the instruments have visible tree rings showing on the plate that are only a few years older than the instruments.   This means the wood was not aged before making. 

We can also see, just from visual inspection, that the classical Italian makers didn't particularly favor extremely tight grained (slow growing) wood.   They sometimes made from very tight grained wood, and sometimes from wood with unstraight grain, but mostly we observe a preference for wood with very straight clear and moderately tight grain.

1721 Lady Blunt Stradivari violin with characteristic moderately spaced straight grain.

Often enough, it's said that the secret is that there is no secret.   

We will look not to find some single magic bullet secret, but rather to understand the many details that distinguish classical Italian making.

And in reviving classical methods of making and design, we'll keep in mind that the old Italian show a range of techniques, not just one.