Why a Stradivarius violin sounds so good...
Ask anyone who made the world’s best violins and they’ll inevitably answer "Stradivari". But science is beginning to undermine the reputation of this great instrument maker whom, it seems, might owe at least part of his success to an attempt at chemical pest control, rather than just his craftmanship.
Antonio Stradivari was born in 1644 and lived in Cremona, a city in northwest Italy. He set himself up as an instrument maker in the 1680’s but his "golden period", during which he is believed to have produced some of his best instruments, didn’t come until the 1700s, by which time he was over 70 years old.
About 600 of his instruments are thought to survive today and in good condition they are each worth at least Aus$5 million. The hefty price tag reflects the fact that, not only are they 300 years old, they’re thought to be genuinely unrivalled in terms of the quality and purity of the sound they produce. Effectively they’re the Rolls Royce Silver Ghosts of the musical world.
Not surprisingly very few owners are willing to donate their instruments "in the name of science" to help researchers find out why they are so special. But it’s been a lifetime ambition of Hungarian-born scientist, musician and violin maker Joseph Nagyvary, who’s also an emeritus professor of biochemistry at Texas A&M University, to do just that. Now, thanks to some tiny wood fragments donated by restorers working on these violins, he thinks he knows the answer.
Nagyvary used a technique called infrared spectroscopy to dissect out the chemical structure of the wood in the fragments. He then compared it with similar samples collected from an old English and an old French instrument dating from the same period.
The results were striking. The trace from the Stradivarius was very different from the other European instruments. It shows signs of having been chemically brutalised. The amount of lignin in the wood was reduced, and the hemi-cellulose, which acts like a molecular bridge holding the wood together, was greatly damaged. This would dramatically alter the resonant properties of the wood and change its acoustics, accounting for the pristine sound that singles out these instruments.
But what could have caused this degradation in the wood? In an attempt to reproduce the effect, Nagyvary tried boiling and even baking samples of modern wood, but the treatment wasn’t harsh enough. Instead, it seems Stradivari, or the carpenter who supplied him, must have resorted to chemical means, probably in the form of copper and iron salts, which are strongly oxidising and could conceivably have damaged the wood in this way.
To find out exactly what chemicals they must have used will require access to more wood fragments, which could take some time. "These samples are hard to get," Nagyvary says. "You cannot approach Itzhak Perlman and ask him to give you a chunk of his Stradivarius for analysis."
But why chemically massacre your future instrument anyway? Nagyvary thinks the answer is all down to a primitive attempt at preservation. "I am a heretic in this regard. I really don't think that Stradivari did this for acoustical purpose. I think that was a rather routine process around that time, in Cremona, where most woodworkers had to preserve their wood against the woodworm. Stradivari was a marvellous craftsman," Nagyvary observes, "but the magnificent sound of his instruments is a lucky accident."
Original reference to Nagyvary’s chemical analysis of a "Strad":
Nagyvary et al., Nature 2006, vol 444: pp 565