Mineral Baths May Have Given Stradivari Their Signature Sound

Turns out the famous violins really are different from modern instruments

This Strad's wood is different from modern-day maple. malerapaso/iStock

For hundreds of years, the sound of Stradivari and Guarneri instruments has been unparalleled, and the instruments are so coveted, they can fetch tens of millions of dollars at auction. But what gives them their signature sound? As The New York Times’ Steph Yin reports, the secret might be in the wood.

In a new study published in the journal Proceedings of the National Academy of Sciences​, researchers reveal that the wood of five Stradivarius and Guarneri instruments is different from that of modern maple. The team used shavings from two Stradivari cellos, two stradivari violins and a single Guarneri violin, assessing their chemical properties using a number of tools.

Not only did they find that the instruments have aged in ways that could improve their sound, but they discovered that the wood used by the master luthiers may have been treated with some kind of mineral bath. The maple seems to have been soaked, perhaps to preserve the wood—a technique that is no longer used by modern-day luthiers.

Hwan-Ching Tai, a co-author on the paper, tells Yin that the bath could have been applied by woodcutters who wanted to ward off fungi before selling the wood. However, it’s impossible for researchers to reconstruct just what kind of treatment or method was used.

There were other differences in the instruments’ wood compared to modern maple, too. For example, researchers found that much of the hemicellulose—a group of complex carbohydrates that strengthen plants’ cell walls—seems to have eroded in the older wood. That could be due centuries of high vibration frequencies generated by musicians playing the instruments, they say. It also seems to account for the instruments’ distinctive sound. Less hemicellulose means a drier wood, which in turn leads to what violinists call a “brilliant” sound.

This isn’t the first time scientists have tried to figure out what makes the instruments tick. Over the years, they’ve used everything from CT scans to assessments of the woodworking techniques thought to be used by the great luthiers to climate studies aimed at determining whether something special happened to the maple trees as they grew. But so far, nobody’s ever been able to replicate the instruments’ infinitely covetable sounds.

That’s cause for concern—especially because the wood of the treasured instruments keeps on aging. In the study, researchers note that the continued decomposition might eventually compromise their sound. For the lucky few who own a Stradivarius, time is ticking…so best to enjoy the music while it lasts.

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