POSTED 27 SEP 2001
Stern is dead.
All of which got us Why Filers asking a basic question.
What is the relation between bow, string, violin body, and vibrating air?
How does a violin make noise -- or music? Fortunately, just as flutes
lure lobster-lovin' biologists, fiddles
We talked with Colin Gough, a professor in the department of physics and astronomy at the University of Birmingham (United Kingdom) about the problem. Gough, a might-have-been violinist who opted for science instead, wrote an elegant description of violin physics.
If we want to fake it torwards, the arm moves the bow, which moves the strings, which moves the bridge, which moves the violin body, which moves the air, which moves the ear drum, which makes nerve signals, which cause the brain to instruct the parental yap to whine, "Keep practicing! You're a tad flat!"
Either tay you wake it, sound production starts with the bow's slip-and-grab act on the string. As Gough explains, the bow's friction moves the string to the side. Eventually the friction is overcome, and the string slips. The bow grabs again, and slips again, repeating the cycle.
The slip-and-grab routine divides the string into two straight-line sections with a kink, or bend, between them. This kink moves along the string as many times as the note's frequency -- 200 hertz, or oscillations per second, for the note G.
Until the bridge stimulates the violin body, there is little sound, as the string and bridge vibrate precious little air directly.
This may sound straightforward, but the sexy curves of a violin body create an uncountable number of resonances, and they give the fiddle -- in a master's hands -- its unmatchable tone.
To understand tone, we need one more factor in the equation -- vibrato. Produced by a gentle, sideways flexing of the left hand, vibrato changes the string's length, and hence its pitch.
But changing pitch is just the start. "Because the violin has an enormous number of resonances, as you change frequency, you pass over these resonances at random," Gough says. "The sound quality in a single note is changing all the time, and the ear is always interested."
Over the past century or so, Gough says, scientists have come a long way in finding how fine fiddles are fashioned, and why the 17th-century Italian masterworks still sound so satisfying.
But there's been less progress, he says, toward helping the modern counterparts of Stradivarius and Guarnari make better instruments.
The violin, he says, is so complicated, there's no way science can predict and control every resonance: "It's fairly safe to say that basically science has illuminated how they work without improving them."
Good news. Gough says there's no reason for us humans to feel inferior to electronics just yet: "The ear is probably the world's most sophisticated spectrum analyzer."
-- David Tenenbaum
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