Together with Andrea Amati and Andrea Guarneri, Antonio Stradivari dominated the so-called Golden Age of Violins (roughly 1660 to 1750), and the devices they crafted stay the gold normal right now by way of acoustic high quality. World-renowned cellist Yo-Yo Ma has lengthy favored a Stradivarius instrument, as does violinist Joshua Bell. However scientists have been arguing for years about exactly why these devices have such superior sound. A recent paper revealed within the journal Angewandte Chemie confirms a concept courting again to 2006: the key lies within the chemical compounds used to soak the wooden, most notably borax, zinc, copper, alum, and lime water.
I’ve written extensively about this topic prior to now. The (perceived) distinctive sound cannot simply be as a result of instrument’s geometry, though Stradivari’s geometrical method did give us the violin’s signature form. One speculation is that Stradivari might have used Alpine spruce that grew throughout a interval of uncommonly chilly climate, which triggered the annual development rings to be nearer collectively, making the wooden abnormally dense. One other prevailing concept has to do with the varnish: particularly, that Stradivari used an ingenious cocktail of honey, egg whites, and gum arabic from sub-Saharan bushes—or maybe salts or different chemical compounds.
Then once more, the distinction could also be all in our heads. A participant’s instrument desire is extremely subjective, and there is some proof of so-called “psychoacoustics” at play: that’s, we have grow to be so awed by the title Stradivarius that it influences how we consider or reply to the sound of considered one of Stradivari’s devices.
In actual fact, a 2012 double-blind study of 21 skilled violinists discovered that a lot of the topics most well-liked taking part in the newer devices; the Stradivarius ranked final of their preferences. Most of them could not inform the distinction between the outdated and new devices, with no vital correlation between an instrument’s age and its financial worth. “Somewhat than looking for the ‘secret’ of Stradivari, future analysis would possibly greatest be centered on how violinists consider devices, on which particular taking part in qualities are most necessary to them, and on how these qualities relate to measurable attributes of the devices, whether or not outdated or new,” the authors concluded.
The varnish concept dates again to 2006, when Joseph Nagyvary, a professor emeritus of biochemistry at Texas A&M College, made headlines with a paper in Nature claiming that it was the chemical compounds used to deal with the wooden—not essentially the wooden itself—that was chargeable for the distinctive sound of a Stradivarius violin. Particularly, it was salts of copper, iron, and chromium, all of that are glorious wooden preservers however may have altered the devices’ acoustical properties. He based mostly his findings on research utilizing infrared and nuclear magnetic resonance spectroscopy to check the chemical properties of the backboards of a number of violins (the backboard is the instrument’s largest resonant element).
In 2007, physicist George Bissinger of East Carolina College used a 3D scanning laser to supply detailed and quantitative measurements of the acoustic properties of a number of Strad violins—primarily mapping out how they vibrate to supply these heavenly tones. Bissinger hung every of the 5 violins by elastic bands, then struck the wooden of the highest plate with slightly hammer whereas recording and measuring the vibrational modes with the scanner.
He particularly wished to measure the in-plane and out-plane movement: the in-plane movement is the supply of a lot of the sound power, and this converts into out-plane movement, which produces the wealthy tonal sounds we affiliate with tremendous violins. As well as, he employed a world-class violinist to play every of the violins used within the research for an hour to get the texture of the devices after which supply subjective scores for each. The musician’s subjective evaluation was then in comparison with the target acoustical information. The ensuing measurements have been sufficiently detailed to reconstruct the stiffness properties of the wooden used to make the Strads, in line with Bissinger.
In 2008, Berend Stoel from the Leiden College Medical Middle within the Netherlands collaborated with a luthier named Terry Borman to take CT scans of a number of Strads, together with a number of trendy devices for comparability. The intention was to check the density of the woods used, since differentials in wooden density influence vibrational effectivity and thereby the manufacturing of sound. Stoel had developed a pc program that noninvasively calculated lung densities in individuals affected by emphysema, and he tailored it to check wooden densities from CT scans.
There wasn’t a lot vital distinction between the typical wooden density of the classical and trendy violins used within the research. However the density variations between wooden grains of early and late-growth wooden was considerably smaller within the classical Cremonese violins in contrast with trendy violins. “Our outcomes clearly doc fundamental materials property variations between the woods utilized by the classical Cremonese and up to date makers,” the authors concluded.
Extra proof in favor of Workforce Varnish got here from a 2016 study by researchers on the Swiss Federal Laboratories for Supplies Science and Know-how (EMPA). They studied how a varnish’s chemical composition, thickness, and diploma of penetration into the wooden affected the acoustics of the instrument.
As I wrote for Gizmodo in 2016:
They used samples of Norway spruce tone wooden reduce from the identical tree and coated the samples with totally different sorts of varnish: two of their very own making, and two utilized by German grasp violin makers. Then they performed vibration checks of the samples over time, utilizing x-ray tomography to measure the results.
The researchers discovered that every one the varnishes elevated the wooden’s dampening means—that’s, how nicely it absorbs and stops vibrations. That additional damping, in comparison with unvarnished wooden, results in a hotter, mellower, and aesthetically pleasing sound. The varnishes favored by German luthiers carried out barely higher in that regard, and likewise made for higher sound radiation (louder tones).
A 2017 study by Taiwanese researchers in contrast the maple utilized by Stradivarius with trendy, high-quality maple wooden. Their evaluation confirmed proof of chemical remedies within the type of aluminum, calcium, and copper, amongst different parts. And due to the decomposition over time of a wooden element known as hemicellulose, the Stradivari and Guarneri devices used within the research had 25 p.c much less water than trendy devices. “That is essentially necessary as a result of the much less moisture, the extra good the sound,” Nagyvary told The New York Times.
This newest research analyzes hint chemical compounds preserved within the maple wooden used to make the soundboards of Stradivari and Guarneri devices. The analysis concerned a uncommon assortment of Cremonese wooden samples of spruce and maple utilized by Stradivari, Guarneri, and Amati, and the outcomes have been then in comparison with trendy spruce and maple tonewoods, in addition to woods from vintage Chinese language zithers and fewer distinctive outdated European violins.
They discovered traces of borax and a number of other steel sulfates within the wooden samples courting between 1600 to 1750. As David Bressan explained over at Forbes:
Borax, also referred to as sodium-borate, happens naturally in evaporite deposits produced by the repeated evaporation of seasonal lakes. Borax remains to be used right now in numerous family laundry and cleansing merchandise, and prior to now was used additionally as an insecticide and fungicide, killing pests. Copper and zinc sulfates, typically related to copper ore, doubtless served the identical goal. Alum, an evaporite mineral containing sulfur, aluminum, potassium and sodium, was added to the combination to type a weak acidic atmosphere within the wooden, stopping mildew development. Halite, frequent desk salt, was added as moisture management, preserving the wooden too dry for microbes and fungi, and on the identical time stopping the deformation of the instrument brought on by humidity fluctuations.
That is welcome information to Nagyvary, who co-authored this newest paper. “This new research reveals that Stradivari and Guarneri had their very own particular person proprietary methodology of wooden processing, to which they might have attributed a substantial significance,” he told Texas A&M Today. “They might have come to appreciate that the particular salts they used for impregnation of the wooden additionally imparted to it some helpful mechanical power and acoustical benefits. These strategies have been saved secret. There have been no patents in these occasions. How the wooden was manipulated with chemical compounds was not possible to guess by the visible inspection of the completed product.”
Nagyvary nonetheless thinks extra analysis is required to shed additional gentle on the connection between the chemical compounds used to deal with the wooden and the sound high quality of the completed devices. “First, one wants a number of dozens of samples from not solely Stradivari and Guarneri, but in addition from different makers of the Golden Interval (1660-1750) of Cremona, Italy,” he said. “There must be higher cooperation between the grasp restorers of vintage musical devices, the very best makers of our time, and the scientists who’re performing the experiments typically professional bono of their free time.”