Mycowood for Maestros: Fungal Violins
• Hankering for a Stradivarius but don’t have 5 million dollars to spare? Produced in Italy around the turn of the 18th century, only ~600 of these prized violins remain. Their secret lies in the “Little Ice Age” (1645 -1715) when Europe suffered long winters and cool summers which caused trees to grow slowly and uniformly : ideal conditions for producing wood with excellent acoustic qualities. Low density, high speed of sound and a high modulus of elasticity, these qualities are essential for ideal violin tone wood.
• Traditionally, wood used in the manufacture of musical instruments is treated with primers, varnishes or minerals to strengthen the adhesion between cell layers. Unfortunately, they also clog up the cell lumen and reduce the speed of sound. The increase in density has an adverse affect on the radiation ratio (R= speed of sound (c)/density (ρ)), reducing the speed of sound and its resonance frequencies.
• Fungus Amongus! Swiss researcher, Prof. Schwarze has discovered that two species of fungi (Physisporinus vitreus and Xylaria longipes) decay Norway spruce and sycamore in a way that their tonal qualities are improved. “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.” Don’t worry, the fungi are fumigated with a dose of ethylene gas before the violins are crafted. In blinded tests, experts preferred the fungal violins over the Strads! O.o
• Think you can pick out the fungal magic?
Take the audio test here: http://goo.gl/BCnVO
Images: Left, Norway Spruce (untreated on top, treated for 12 wks below); Right, sycamore (untreated top left, treated top right). From, Schwarze et al. Superior wood for violins- wood decay fungi as a substitute for cold climate. New Phytologist (2008) 179: 1095–1104
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