How rare are Stradivarius violins

Violin making: why does a Stradivarius sound so good?

Instruments made by Antonio Stradivari still sound inimitable today. Why is that? Researchers have proven special properties in wood

Star violinists like Anne-Sophie Mutter or David Garrett swear by their unique sound. What is the basis of the secret of the instruments that Antonio Stradivari built around three centuries ago is still controversial today: It is due to the wood, some researchers claim, to the shape of the sound holes or to the varnish that Stradivari used, others say. In the meantime there are even more voices claiming that the special sound is just a myth: “Blindly” one cannot distinguish the instruments.
But now there is probably empirical evidence for special properties in wood. Hwan-Ching Tai, professor of chemistry at National Taiwan University, and a team examined the wood of four Stradivarius instruments, two violins and two cellos.

Known to a few initiates during Stradivari's lifetime

In all of the wood samples, he and his colleagues found minerals containing aluminum, copper and zinc - traces of chemical treatment. Tai suspects that this type of woodworking was a tradition that was lost over time. It is possible that she was only known to a circle of initiates during Stradivari's lifetime.
In any case, this included Giuseppe Guarneri, violin maker and contemporary of Stradivari, who, like the latter, lived in the northern Italian city of Cremona. The same mineral traces were found in the wood of the Guarneri violin, which Tai and his team also examined.
Both masters of violin making used treated wood, but whether they did this consciously is an open question. Tai and his team also believe that the mineral treatment was a method used by forest workers to protect the wood from pests.
In any case, she strengthened the wood and thus presumably refined the sound of the instruments.