Dr. Chitwood said that a violin’s shape affects its sound far less than other attributes — like the varnish and the properties of the wood — although this hasn’t stopped luthiers from putting their own creative stamp on the instrument’s form. In this way, Mr. Chitwood pointed out, the shape of a violin is much like a neutral trait in genetics, which scientists may sometimes use to trace the path of evolution.

In the case of violins, that evolution began in Brescia, Italy, in the late 16th and early 17th centuries, where masters like Giovanni Paolo Maggini helped pioneer the design of violins. But the shape of these early violins — narrow bodies and rounded corners — would not dictate those of future instruments.

That honor went to Stradivari, who worked in Cremona, Italy, in the 17th and 18th centuries. He was the first luthier in Mr. Chitwood’s sample to produce a broader body style and more defined corners. Although Stradivari’s work was highly respected during his lifetime, his influence did not become dominant until the 19th century, when Parisian luthiers like Nicolas Lupot and Jean-Baptiste Vuillaume set out to copy his work.

“Lupot and Vuillaume thought in their hearts that Stradivaris were the best instruments ever,” Dr. Chitwood said. “They dedicated their lives to figuring out things like the family secrets for the varnish and trying to find the right wood types that matched his. And of course they thought that shape was important.”