Fresh chemical clues emerge for the unique sound of Stradivari violins

The rich sound quality of Antonio Stradivari's violins has been enjoyed by musicians and music lovers for a long time. Stradivari violins seem to sound better than modern instruments in part because scientists have been interested in it for decades.

According to a recent paper published in the journal Analytical Chemistry, the wood's natural resonance may be influenced by aProtein-based layer at the interface of the wood and the varnish. A paper published in the Journal of the Acoustical Society of America shows that the sound of older violins can affect the perception of musical tones.

You can read a summary of some of the research I've written about in the past here. The violin's signature shape can't be solely attributed to the instrument's geometry. One hypothesis is that Stradivari may have used Alpine spruce that grew during a period of uncommonly cold weather, which caused the annual growth rings to be closer together. Stradivari may have used a cocktail of honey, egg whites, and gum arabic from sub-Saharan trees to make the varnish.

The varnish has received a lot of attention. The theory dates back to 2006 when Joseph Nagyvary, a professor at Texas A&M University, made headlines with a paper in Nature claiming that it was the chemicals used to treat the wood that caused the unique sound.

It was salts of copper, iron, and chrome, all of which are excellent wood preservers, but may have altered the instruments' acoustics. The chemical properties of the backboards of several violins were studied with the help of nuclear magnetic resonance Spectroscopy.

The Swiss Federal Laboratories for Materials Science and Technology (EMPA) conducted a study in 2016 that supports Team Varnish. The acoustics of the instrument were studied how a varnish's chemical composition, thickness, and degree of penetration affected them. The researchers found that the wood's ability to absorb and stop sound was increased by the use of varnish. They found evidence of treatments in the form of aluminum, calcium, and copper.

The soundboards of Stradivari and Guarneri instruments were analyzed last year. The research involved a rare collection of Cremonese wood samples, which were compared to modern and antique Chinese zithers and less exceptional old woods. Bruce Tai told Ars last year that the key to reproducing Stradivari's tone was the chemical processing of wood.