Scientists solve centuries-old mystery behind Stradivari’s legendary violin sound

Have you ever wondered what makes an old Italian violin sound so special? For centuries, musicians and scientists have puzzled over the unique qualities of instruments made by masters like Antonio Stradivari and Giuseppe Guarneri “del Gesù”.

These violins, crafted in Cremona, Italy, hundreds of years ago, are still preferred by top performers today. Even with all our modern advancements, we haven't quite figured out how to replicate their amazing sound.

For over 200 years, experts have debated why Cremonese violins are so unique. Some blind listening tests, where people can switch between recordings, have favored Stradivari violins. However, other tests with live performances haven't shown the same clear preference.

This ongoing debate highlights how complex the sound of these instruments truly is. Many have suggested that the Cremonese masters used secret techniques, now lost, to create their masterpieces. Scientists have mostly looked at the shape and varnish of these violins. But simply copying these features hasn't been enough to reproduce their special playing qualities.

The soundboard of a violin is its most important part for making sound. It also has to be incredibly strong to handle the tension from the strings, which can be around 8 kilograms of force. Modern violin makers usually copy the shapes of Stradivari and Guarneri soundboards. But they often make them thicker.

A typical modern soundboard is about 3.0 millimeters thick, or even up to 3.5 millimeters. In contrast, Stradivari's soundboards were usually between 2.0 and 2.8 millimeters thick, and Guarneri's were 2.2 to 2.9 millimeters. While some older soundboards might have been thinned later, their combination of thinness and durability points to special material properties.

This suggests that the unique qualities of these violins weren't just due to the type of wood or how it was chosen. Spruce and maple, the woods used, are still common in Europe. Also, CT scans show that the density of these woods is similar in old Cremonese and modern instruments. This led researchers to believe that the distinctive properties came from some kind of artificial treatment.

Recent studies have found unusual chemical makeups in the maple wood of Stradivari and Guarneri violins. However, it was unclear what chemicals were used or who applied them. This prompted an international team, led by Hwan-Ching Tai, a chemistry professor at National Taiwan University, to analyze a rare collection of Cremonese wood samples.

These samples included both spruce and maple from the major Cremonese violin-making families: Amati, Stradivari, and Guarneri. They compared these samples to modern violin woods, as well as aged wood from ordinary old violins and even ancient Chinese instruments.

The research confirmed a long-held theory by Joseph Nagyvary, professor emeritus of biochemistry at Texas A&M University. About 40 years ago, Nagyvary first proposed that chemicals used to treat the wood, not just the craftsmanship, were key to the violins' unique sound. He believed this was partly due to widespread worm infestations at the time, which would have threatened the wood.

"All of my research over many years has been based on the assumption that the wood of the great masters underwent an aggressive chemical treatment, and this had a direct role in creating the great sound of the Stradivari and the Guarneri," Nagyvary stated. His initial findings were even verified by the American Chemical Society.

The current research by Professor Tai's team supports Nagyvary's theory, identifying several chemicals used to treat the wood. These include borax, zinc, copper, alum, and lime water. Nagyvary notes that "Borax has a long history as a preservative, going back to the ancient Egyptians, who used it in mummification and later as an insecticide."

The presence of these chemicals suggests a collaboration between violin makers and local pharmacists. Both Stradivari and Guarneri likely wanted to protect their precious wood from worms.

Nagyvary believes that each violin maker probably had their own special methods. "This new study reveals that Stradivari and Guarneri had their own individual proprietary method of wood processing, to which they could have attributed a considerable significance," he explained. He thinks they realized that the special salts they used also made the wood stronger and improved its sound.

These methods were kept secret, as there were no patents back then. You couldn't guess how the wood was treated just by looking at the finished violin. Nagyvary also points out that varnish recipes were not secret because varnish doesn't significantly affect the tone quality.

However, the process of treating fresh spruce planks with water-based chemicals was crucial for the final sound. This knowledge gave them a competitive edge over other instrument makers. The team found these chemicals were not just on the surface but all through the wood, directly impacting its sound quality.

Antonio Stradivari made about 1,200 violins during his lifetime, selling them to the very wealthy. Around 600 Stradivari violins still exist today. Guarneri del Gesù, a less famous contemporary, struggled to sell his instruments. Yet, today, his violins are considered just as good, and often as valuable, as Stradivari's. "Their violins have been unmatched in sound and quality for 220 years," Nagyvary observes. A Stradivari violin can be worth $10 million, and a Guarneri can be worth even more.

Further research is needed to fully understand how these chemicals and the wood created such pristine tonal quality. Nagyvary emphasizes the need for more samples from the "Golden Period" of Cremona (1660-1750). He also calls for better cooperation between antique instrument restorers, modern violin makers, and scientists.

Nagyvary himself has spent much of his 87 years researching violins, having even learned to play on an instrument that once belonged to Albert Einstein. The secrets of the Cremonese masters are slowly being unveiled, showing that their artistry extended beyond craftsmanship to a sophisticated understanding of materials science.

Research findings are available online in the journal Angewandte Chemie International Edition.

Note: The article above provided above by The Brighter Side of News.

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