Stradivarius stringed instruments—the finely constructed, highly sought after multi-million dollar wood boxes* crafted in the 17th and 18th century by Italian luthier Antoni Stradivari—are a bit of a mystery to modern day observers. Despite their quality, nobody quite knows what makes them so superior.
Researchers at National Taiwan University, however, think they might have an answer. According to a study published this week in the Proceedings of the National Academy of Sciences, it’s all about the wood, baby.
After examining maple samples from four Stradivari and one Guarneri (a similarly well-regarded instrument), the authors discovered that the wood had been chemically treated—the samples contained traces of aluminum, calcium, copper, sodium, potassium, and zinc.
“This type of chemical seasoning was an unusual practice, unknown to later generations of violin makers,” the authors concluded. “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.”
According to Henri Grissino-Mayer, a professor at the University of Tennessee, Knoxville, who studies tree rings, modern instruments don’t get these kinds of baths. “This paper is the first to convince me that some type of mineral infusion into wood might cause superior sound in a musical instrument,” he told the New York Times.
It remains a mystery, however, whether the famed luthiers knew what kind of effect the chemical treatments would have. Hwan-Ching Tai, one of the study’s authors, posited that the chemical bath was probably initially performed by forest workers who wanted to avoid fungus and worms.
Besides the chemical composition, the researchers also found that a third of hemicellulose, a component in wood that sucks up moisture, had decomposed. As a result, the instruments had roughly 25 percent less moisture than newer versions—a key contributor for their “brilliant sound,” according to luthier Joseph Nagyvary.
Still, as the Washington Post points out, the debate over how the famed instruments get their sound isn’t over, as chemistry doesn’t account for acoustic effects—how the instruments actually vibrate and produce sound. And some even think all the fuss is for nothing: A 2012 study, for example, found that 21 players preferred a modern instrument over an older one when they weren’t told which was which.
In other words, if you try to give your violin a bath, you’re probably going to have a bad time.
*I used to play the violin, a Very Good Wooden Box, so I am allowed to call them this.