String instruments created by the Italian master craftsmen of the late 17th and 18th centuries are believed by many experts to sound more beautiful than all others. Now however, researchers suggest that the world's most famous violinmaker, Antonio Stradivari, and his contemporaries may have benefited not only from unparalleled ability, but also from a severe cold spell which gripped Europe for 70 years.
Theories on what makes a Stradivarius a Stradivarius include secret varnishes, wood taken from ancient castles, or special drying techniques. But these haven't stood up to scrutiny. According to a paper in the current Dendrochronologia, the reason may be that they failed to take into account a unique climatic spell, called the Maunder minimum, that began in 1645, 1 year before Stradivari's birth. This period was characterized by a reduction in sunspots and other solar activity, long winters, cool summers, and consequentially slow, even tree growth.
Climatologist Lloyd Burckle of Columbia University in New York and tree-ring scientist Henri Grissino-Mayer of the University of Tennessee, Knoxville, argue that local environmental conditions such as altitude and soil quality, along with climate, might help explain the awesome acoustics. The craftsmen would have used local wood with narrow tree rings--desirable properties in high-quality violins, because the wood is more dense, and thus more resonant, says Grissino-Mayer. Other research has shown that many Stradivarius violins are built from spruce wood contemporary with his lifetime.
Such a local combination of environment and climate has not occurred since Stradivari's "Golden Period," according to the researchers. However, the materials alone aren't what made the instruments so special. "We can't discount the extraordinary skills and craftsmanship of these violinmakers," says Grissino-Mayer.
It's exceedingly difficult to find measurable differences in the tonal quality of the cherished old violins and more ordinary ones, let alone explain what causes them, comments Colin Gough, physicist and expert on musical acoustics at the University of Birmingham, U.K. Gough sees problems with the new study. For example, he says, no one has demonstrated that denser wood is actually more resonant.