Why does a violin made by Stradivari or Guarneri sound so amazing? So rich and pure, so consistently penetrating and powerful from the lowest note to the highest?
There are plenty of theories about what's behind the glorious sound of violins made in Cremona, Italy in the late 1600s and early 1700s. It's a secret varnish recipe and the ground coat over the varnish, it's odd glue, the filler. No wait, it's the wood preservative. Or unique maple from northern Croatia. Or wood stolen from old cathedrals. It's the special arched shape of the violin's underside, the shape of the f-holes on top. It's the fungus in the wood, it's ammonia-treating the wood, it's borax, it's tung oil. It's varnish made from urine.
The great violinist Nicolo Paganini made the poetic claim that Antonio Stradivari only used "the wood of trees on which nightingales sang."
Of course the real answer is: no one knows. But a recent theory that has held up longer than most is that the "Little Ice Age" from the mid-1600s to mid-1700s brought cooler temperatures, which meant a shorter growing season, and wood with a more consistent density.
That theory was reinforced by a study released last week. A group of Dutch researchers teamed with a violinmaker from Arkansas to run both new and old violins through a medical device, a CT scanner. They found that the wood in the 300 year-old violins from Cremona is not denser, but crucially, it has more CONSISTENT density, which makes for a sweeter sounding board.
(Credit: Stoel BC, Borman TM, doi:10.1371/journal.pone.0002554)