Another string has been added to the bow of the great Stradivarius debate. For years, musicians and scientists have disputed what makes the tone of the 600 surviving instruments by the renowned violinmaker so unique. Theories abound, from the quality of the wood to the shape of the instrument. Or perhaps, some claimed, a secret ingredient in the wood varnish – such as egg, animal-hide proteins, precious stones or sugar – held the key to the mystery.
But a four year study has confirmed that the varnish used by Antonio Stradivarius (1644-1737) and his colleagues was in fact a simple mix of oil and resin. ‘It’s a very basic recipe,’ says Jean-Philippe Echard, a chemist at the Musée la Musique in Paris who participated in the study. ‘There’s been talk of fossil amber or propolis, which is produced by bees. But we haven’t found any of these ingredients.’
Echard and fellow researchers in France and Germany carried out the study on five instruments – four violins and a viola d’amore – made between 1692 and 1724. They examined the samples under infra red light, and were able to identify two layers of varnish. The first was simply oil based, while the second was a mixture of oil and pine resin, with red pigments added in all but the earliest instruments.
This is a similar technique to that used by contemporary painters, and suggests the varnish was simply used to give the instruments a rich colour. ‘There is no indication that allows us to say that the lacquer has an influence on sound,’ Echard said. ‘The ingredients were so simple, so probably the skill was in his hand and eye.’