Can anyone actually hear the difference in a Stradivarius?

Mostly, no. In blind tests from 1817 to 2014, listeners have never reliably told a Stradivarius from a high-quality violin by another maker, and acoustic analysis hasn't found the difference either. A Stradivarius is a masterpiece of craftsmanship and history, worth millions, but its magic seems to live at least partly in our expectations.

The tests are delightfully humbling. In 1977 the BBC asked the great violinists Isaac Stern and Pinchas Zukerman, plus a leading violin dealer, to identify four instruments played behind a screen: a Stradivarius, a Guarneri, a 19th-century French violin and one made the year before in Britain. None of them got more than two right, and two picked the brand-new violin as the Stradivarius. In 2009 a modern violin made from fungus-treated wood won 90 of 180 audience votes, far ahead of a 1711 Stradivarius, and most listeners thought the winner was the Strad.

The most careful study, published in 2014, had ten star soloists play old Italian and new violins while wearing welders' goggles in dim light. Their favorite was a new violin, and they couldn't tell old from new better than chance. Some violinists object that such tests are too short or not expert enough, and the debate goes on.