Berlin, Germany
These instruments are, of course, famous for the quality of their sound, and there have been many
attempts to explain and reproduce this quality, largely without success.
Over the centuries, numerous theories have been presented, and debunked, including an assertion that
the wood was salvaged from old cathedrals. Dendrochronology, or tree-ring dating, has proved this false.
A more modern theory attributes tree growth during a time of unusually low solar activity during the Maunder Minimum "Little Ice Age" from ca. 1645 to 1750. During this period, temperatures throughout Europe were much cooler causing stunting and slower tree growth with unusually dense wood. Further evidence for this "Little Ice Age theory" comes from a simple examination of the dense growth rings in the wood used in Stradivari's instruments.
Two researchers, Henri Grissino-Mayer, a University of Tennessee tree ring scientist and Lloyd Burckle, a Columbia University climatologist, published their conclusions supporting the theory on increased wood density
in the journal Dendrochronologia.
Yet another possible explanation is that the wood originated and was harvested from the forests of northern Croatia. This maple wood is known for its extreme density due to the slow growth from harsh Croatian winters. Croatian wood was a commodity traded by Venetian merchants of this era and is still used for crafting musical instruments by local luthiers to this day.
Some research points to wood preservatives being used in that day as contributing to the resonant qualities.
While the sound of Stradivari's instruments still has not been fully explained by modern research tools, devices such as the scanning laser vibrometer are aiding researchers in testing the theory that the careful shaping of belly and back plate, in order to "tune" their resonant frequencies, may be an important factor.
Glues and varnishes used by Stradivari have been analyzed extensively, and have also been attributed for the sound and quality of his instruments. There remains no consensus on the single most probable factor, and most likely, it is some combination of all, and something not yet recognized.
On July 2, 2008 it was reported that using a computed tomography scanner, a Dutch doctor and an Arkansas violin maker have found that the remarkably even density of the wood may hold the key to the intruments famous sound.
