Centuries-old Stradivarius violins are some of the world's most revered instruments, fetching millions of dollars apiece. Professionals violinists argue that the ultra-high-end stringed instruments simply sound better than run-of-the-mill violins, with unrivaled tonal ranges and acoustics. But research featured in the Proceedings of the National Academy of Sciences presents a "striking challenge to conventional wisdom": In a blind study, concert violinists didn't prefer the Stradivarius' sounds to those made by newer violins. Here, a brief guide:

What makes Stradivarius violins so special?
The violins were built between 1690 and 1720 by master luthier Antonio Stradivari. Only 700 are known to exist today. Scientists studying the violins have argued that the instruments' reputed superiority may have something to do with the unusually dense wood in Northern Europe at the time, a so-called "Little Ice Age" which caused trees to grow with a consistent, uniform denseness. Another theory credits the unique chemical varnish applied by Stradivari, apparently a collaborative effort between the luthier and local druggists. 

So what happened in this experiment? 
At the Eighth International Violin Competition of Indianapolis, a "prestigious gathering" of violinists and violin experts, 21 subjects were tested to see if they could pick out the Stradivariuses from a group of instruments, says Kate Shaw at Ars Technica. The subjects were presented with three new violins and three super-expensive, antique violins (two made by Stradivari, and one crafted by a rival violin maker during the same time period). Violinists wearing modified welding goggles were sequestered in a dimly-lit room; a drop of perfume was dabbed on each violin's chin-rest to mask the instrument's scent. The experiment was "carefully designed" so that neither researchers nor the musicians knew which instrument was which — a true "double-blind." The musicians were asked to play the instruments and rank them according to playability, projection, response, and tone.

And the results?
It turns out that the professional players "mostly preferred new instruments," says the Sydney Morning Herald, "and overall they were least keen on one of the two Stradivarius instruments." 

Does this destroy Stradivari's reputation?
Not quite. The test, while fascinating, has its failings, says Steve Isserlis at Britain's Guardian. It was rather rushed, for one: It takes time for professionals to understand the nuances of an instrument, says Isserlis. "We players have to learn to relate to these magnificent works of art to bring out the deep layers of sound that distinguish a great instrument from a good one."

Sources: Ars Technica (2), GuardianSydney Morning Herald