Stradivari meets science

Tree rings reveal instruments’ shared roots

Antonio Stradivari has gone down in history as the creator of some of the best-​sounding stringed instruments ever made. Of the over 1,100 violins, cellos, violas, guitars, and harps he made in his lifetime (1644–1737), about 650 have survived into the 21st century. Today, “Strads” remain favorites of top-tier musicians.

It’s thought that Stradivari learned his craft from Nicola Amati. However, tangible evidence linking the luthiers is limited to a single Stradivari violin bearing the label Antonius Stradivarius Cremonensis Alumnus Nicolaij Amati, Faciebat Anno 1666.

Well, that, and the fact that scientists confirmed last year that both men used wood from the same tree (Dendrochronologia 2022, DOI: 10.1016/j.dendro.2022.125960).

Mauro Bernabei and his colleagues at the National Research Council of Italy used a high-resolution camera to record the growth-ring pattern—essentially a tree’s fingerprint—in the soundboard wood of a Stradivari harp from 1681.

This technique, known as dendrochronology, is highly useful for establishing provenance for wooden artifacts—provided there’s a solid reference chronology for the type of wood and the region it was grown in, Bernabei tells Newscripts. He once used it to determine the maker of a violin by analyzing photos sent to him on WhatsApp (Herit. Sci. 2021 DOI: 10.1186/s40494-021-00521-4).

Analyzing the harp was tricky because of its narrow shape, Bernabei says, but he and his team managed to get a read on the pattern.

Comparing it with other instruments made in the region around the same time, the researchers found that the harp’s tree-ring fingerprint matched that of a 1679 Amati cello, meaning it’s likely the two soundboards were made of wood from the same tree.

However, Bernabei cautions, this doesn’t definitively prove that Stradivari and Amati worked together— perhaps they simply bought wood from the same supplier. “This is not a smoking gun,” he says. “It’s a clue.”

Strads’ secret proteins

While Stradivari’s success might have had something to do with his meticulous choice of wood or with the climate conditions around the turn of the 18th century creating particularly resonant trees, it’s believed that the treatments and finishes he applied to the wood are what make his work extraordinary. So scientists are subjecting Strads to all manner of analytical methods in hopes of uncovering the master’s chemical secrets.

Some studies have hinted at a layer under the varnish meant to smooth out the wood—and thus the sound—but its composition has eluded researchers.

Scientists recently took a nanoscale look at that underlayer on two violins and found traces of animal protein (Anal. Chem. 2022 DOI: 10.1021/acs.anal​chem.2c02965). Their method of choice was infrared scattering-type scanning near field optical microscopy, which combines infrared spectroscopy and atomic force microscopy to investigate materials.

They found tiny patches with unmistakable protein IR signals on both violins, “just absorbed in the first row of wood cells,” Chiaramaria Stani, a scientist at the Central European Research Infrastructure Consortium who did the nanoscopic analysis, tells Newscripts.

Stani says the IR spectrum looks like collagen or casein, so the protein is likely from some kind of animal-based glue. And so the quest to understand the chemical composition of Stradivari’s coatings continues.

Please send comments and suggestions to newscripts@acs.org.