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Treatment with fungi makes a modern violin sound like a Stradiavarius
A good violin depends not only on the expertise of the violin maker, but also on the quality of the wood that is used. The Swiss wood researcher Professor Francis W. M. R. Schwarze (Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland) has succeeded in modifying the wood for a violin through treatment with special fungi. This treatment alters the acoustic properties of the instrument, making it sound indistinguishably similar to a Stradivarius. In his dinner talk at the 1st ECRC “Franz-Volhard” Symposium of the Max Delbrück Center for Molecular Medicine (MDC) and Charité – Universitätsmedizin on September 7, 2012 in Berlin-Buch, Schwarze reported on his research and gave a preview of what his wood treatment method could mean, particularly for young violinists.
Low density, high speed of sound and a high modulus of elasticity – these qualities are essential for ideal violin tone wood. In the late 17th and early 18th century the famous violin maker Antonio Stradivari used a special wood that had grown in the cold period between 1645 and 1715. In the long winters and the cool summers, the wood grew especially slowly and evenly, creating low density and a high modulus of elasticity. Until now, modern violin makers could only dream of wood with such tonal qualities.
Professor Schwarze’s developments could soon make similarly good wood available for violin making. He discovered two species of fungi (Physisporinus vitreus and Xylaria longipes), which decay Norway spruce and sycamore – the two important kinds of wood used for violin making – to such an extent that their tonal quality is improved. “Normally fungi reduce the density of the wood, but at the same time they unfortunately reduce the speed with which the sound waves travel through the wood,” the researcher explained. “The unique feature of these fungi is that they gradually degrade the cell walls, thus inducing a thinning of the walls. But even in the late stages of the wood decomposition, a stiff scaffold structure remains via which the sound waves can still travel directly.” Even the modulus of elasticity is not compromised; the wood remains just as resistant to strain as before the fungal treatment – an important criterion for violin making. Before the wood is further processed to a violin, it is treated with ethylene oxide gas. “No fungus can survive that,” Professor Schwarze said. That ensures that fungal growth in the wood of the violin is completely stopped.
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This video is on fungi, including Xylaria longipes.