How much chemistry is in the wood of a Stradivarius? Researchers have found telltale marks on the Lombard masters' instruments - marks absent on others. But is that really the secret of the coveted miracle of sound?
"Take the wood of a tree felled at new moon and a pinch of borax crystal. Add three drops of a maiden's urine…" No, this is not an excerpt from the building instructions for a witch's broom, but the list of ingredients for one Stradivarius – at least in the imagination of some imaginative violin enthusiasts. It cannot have been mysterious enough for some when the great masters from Cremona in Lombardy made their precious instruments. Whatever makes the sound of their violins so unmistakable, it can be said that Antonio Stradivari, Andrea Guaneri and the others took their knowledge to the grave with them.
However, the old masters would have found the methodology with which scientists today use high technology to trace the arts and crafts of the past mysterious. From computer tomographs to laser measuring devices to infrared spectroscopy - there is hardly an analysis device that hasn't had one of the violins from the heyday of 1520 to 1750. Because no one can afford to disassemble one of the rare instruments just for research reasons. Modern measuring equipment also allows the components to be analyzed largely non-destructively using the smallest of samples.
In the eyes of many, the paintwork in particular is the solution to the riddle, even if crucial questions remain unanswered. The local pharmacist, some suspect, supplied the instrument makers with substances that were newly discovered at the time. They could have positively influenced the vibration behavior of the instruments - but how exactly is unclear. For example, a network-like linkage of long-chain sugar molecules and borax s alts on the wood surface is under discussion. But whether that would actually affect the sound quality cannot be said with certainty. The function of the layer of ash underneath the paintwork cannot be determined unequivocally either. Should it possibly only protect the wood from fungal attack?
It might seem more plausible to locate the ominous "secret" in the wood itself. Of course, it doesn't come from ancient cathedrals, as some have claimed, nor from extinct tree species, research has shown that much. Nevertheless, it has a number of interesting properties: Because it grew during a particularly cold phase of the "Little Ice Age", which broke out in Europe from the 14th to the 20th century.brought cold summers and severe winters up to the 19th century, it had a different structure than today's comparatively fast-growing wood. And certainly the great master violin makers used the highest quality material that was available. The long storage time that was common at the time then did its part to further improve the quality.
The wood of the Stradivari is extremely rigid and yet light and of low density - just as modern violin makers imagine the ideal material. But is that enough to explain the euphony of the instruments? Experts like Joseph Nagyvary from A&M University in Texas are skeptical. His hypothesis: The acoustic properties of the tonewoods have been subsequently improved through chemical pre-treatment.
Nagyvary can rely on an examination of material samples from various historical tonewoods. Using nuclear magnetic resonance imaging and infrared spectroscopy, he detected residues that indicate oxidative and hydrolytic conversion processes - processes that change the fine structure of the wood and thus not only make it more durable, but could also have changed its acoustic properties. It is quite possible that the luthiers appropriated a regional tradition of preserving wood and adopted it for their own purposes, claims Nagyvary.
The convincing thing about his study is that corresponding traces of substance could only be found in exactly two of the violins: the first a Stradivarius, the other a Guarneri del Gesù. Both instruments come from the famous manufactures in Cremona, while violas and violins from English and French production delivered negative results, as did modern violin wood, which was also tested for reasons of comparison. A Stradivarius cello turned out to be something in between with only the slightest residue of the substances in question.
But what were the secret ingredients responsible for the residues discovered? No one knows anything for sure, admits Nagyvary. Even the question of whether the old masters deliberately treated the wood at all must remain open. Because it has long been known that the wood often floated in the water of the Venice Lagoon for months after being transported. No one who has ever seen the lagoon will doubt that one or the other mysterious molecule swam across their path - today as three hundred years ago.
And there's something else Mr. Nagyvary can't explain: why he's still searching for the ultimate trick of the old masters. Not only does his name sound like Stradivarius, his violins do too. For several years he has been building instruments that are confusingly similar to the original. He faced the direct test a long time ago: alternately his and Stradivari's violins were played covertly to an audience of experts and non-experts alike. Drawn, according to the survey of the viewers. Maybe the Nagyvary did even better.
German instrument makers are also successfully copying the sound of the coveted violins and without any mysterious miracle cures. The Bonn-based Stefan-Peter Greiner, for example, analyzes the historical models together with the physicist Heinrich Dünnwald and converts his findings into instruments that are among the best in the world - including all Stradivarius, Guarneris and Amatis.
Solid, albeit excellent craftsmanship and experience gained over centuries may therefore be an - admittedly sober - explanation for their fascinating sound. Why has nobody built a comparable top violin since the times of the old masters? No need, there were already some.