PLoS One 3, e2554 (2008)


Subtle shifts in density that occur within individual pieces of wood might help to explain why violins made in eighteenth-century Cremona, Italy, sound so special.

Berend Stoel, of Leiden University Medical Center in the Netherlands, and Terry Borman, a violin maker based in Fayetteville, Arkansas, measured the density of five classical violins — including two made by Antonio Stradivari (such as that pictured right) — and eight modern instruments, using computed tomography. The difference in density between spring- and summer-growth spruce and maple was significantly smaller in the classical instruments than in the modern ones. Stoel and Borman suggest that these variations in density may influence the wood's acoustic properties by affecting its stiffness.