The authenticity of prized musical instruments like Stradivarius violins can hinge on arguments over assembly, style and varnish. Tree-ring analysis can help settle such disputes, but it, too, has its limitations.
A tree's annual growth rings show its age; variations in the rings' width and spacing reveal where it grew.
Matching that fingerprint to a violin's wood grain can peg an instrument's earliest birthday — which ideally falls before Antonio Stradivari died in 1737.
"If the outermost ring of a violin's board is after 1737, then certainly this is not a Stradivari instrument," said Paolo Cherubini of the Swiss Federal Institute for Forest, Snow and Landscape Research WSL in Birmensdorf, Switzerland.
Cherubini, who also teaches at University of Zurich, wrote the article in the journal Science to clear up confusion in the art and music worlds regarding the strengths and limits of dendrochronology.
Consider one much-debated example, the violin called "Messiah." Initial tree-ring findings placed its creation after Stradivari's death. But Paul Sheppard of University of Arizona's Laboratory of Tree-Ring Research later helped show it predated the Italian luthier's demise.
Shepherd said rings lost during assembly make violin dating difficult, as does the wood's cut, which is like a pie slice instead of the preferred cross-section.
"But that's the view — the radial view — which the violin has on the front, and that's the only one we're going to get, so we really have to work with that," Shepherd said.
