When violins look down the drain
Perhaps serious musicians should see a doctor before buying a new violin. It might be worthwhile for them to consult a radiologist. This is according to a computed tomography study of 14 top-class stringed instruments, including rare Stradivarius violins and other recognized masterpieces. According to Steven A. Sirr, a radiologist at Abbott Northwestern Hospital in Minneapolis, computed tomography can reveal unexpected defects; In addition, this technology provides new information about the construction of the instruments, as well as characteristic "fingerprints" that can help identify lost or stolen instruments. Sirr presented the study on April 4th. December 1997 at the 83rd Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA).
Damaging these instruments - many are worth more than $1 million - can significantly reduce their value and, most importantly, the quality of their sound, Sirr said. A crack in the soundpost area on a violin's backing plate reduces its value by 50 percent. He emphasizes that defects that are otherwise unnoticeable can be detected using computed tomography. Even counterfeiters now have a harder time: The technology can be used to eliminate doubts about the authenticity of an instrument or even to confirm them.
It can also provide new information for luthiers trying to make instruments that approach the quality of a Stradivarius, Amati and other famous masters. "Two cellos and a viola were built using information obtained from computed tomography," Sirr said. The viola, based on an early 17th-century instrument by Giovanni Paolo Maggini and Gasparo da Salo, recently won a gold medal for craftsmanship and high quality of sound in an international competition.
Computed tomography can also identify unique wood grains that serve as a fingerprint for each instrument. We believe that computed tomography evaluations should be performed before purchasing a first-class instrument and could also play a role in obtaining insurance for these extremely rare and valuable instruments, said Sirr.
Defects of all kinds were detected by computer tomography in all 14 instruments examined: cracks, wormholes, air slots and deformations. Evidence of repairs, such as traces of glue, filling material and wood patches, could also be provided by computed tomography.
One of the most important tasks of the modern violin maker is to evaluate instruments. This is done by carefully examining the outer surfaces and, with the help of mirrors used in dentists, the inner surfaces," Sirr said. It is known that many serious imperfections can be concealed by glue, filler, retouching or varnish. These manipulations can possibly escape even the most careful eye tests; with the help of computed tomography, however, they are revealed.
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