To build a better violin; can scientists determine why some instruments sound great? - Cover Story

Science News, Sept 3, 1994 by Richard Lipkin

Before morning breaks in Montclair, N.J., Carleen M. Hutchins enters the cellar of her rambling Victorian home. There, in her laboratory, she switches on electronic acoustical equipment, then saunters to a chipped workbench on which newly varnished violin fronts are strewn. Beside them are piles of fresh wood shavings. Behind her, cellos line up along a wall.

A tone sounds as she taps the thin, arched top of an instrument. Her hands gauge its delicacy, its thickness, its edges. She takes a tool and shaves away a sliver of wood. Again, she feels and taps the violin's top. Again, a tone sounds. Trained ears listen. Another scrape. Another tap. Now the overtones harmonize mellifluously.

Soon, she will begin tuning the curly maple back of another violin -- tapping, scraping, listening, coaxing it to vibrate at a precise 370 times a second, radiating the perfect blend of sound.

The crafting of fine violins has proceeded for centuries as a secret art, handed down through apprenticeships from generation to generation. It takes 8 years, at least, to train a competent craftsman, decades to hone a master. The great luthiers of 16th to 18th century Italy -- Andrea Amati, Antonio Stradivari, Giuseppe Guarnieri -- understood subtleties that today's makers have yet to decode. Those old masters still reign in music, their secrets embedded within their violins' wooden walls.

The question that has driven Hutchins for the last 45 years sounds simple enough: How did the old masters make so many fine instruments that have set the violin standard of all time?

"I want to know why," says Hutchins, "what mechanisms underlie the great tonal qualities that players hear and feel in an instrument? For many years I've been looking at the relationship between a violin's wood and the air moving within its body as it's played. How do the vibrations of the wood and air affect each other? Is this something we can understand and control? I think so."

In search of answers, Hutchins has studied exhaustively some of civilization's greatest stringed instruments, as well as roughly 400 violins, violas, and cellos she herself has fashioned.

"I think we can find out why great violins sound so good, learn their mechanisms, and use that knowledge to make consistently better instruments," she says. "There's no reason that music students should have to mortgage their futures to own a truly fine-sounding violin."

"Already, some first-rate violin makers have instruments that [after being played for 80 years] may sound better than Stradivari's," she adds.

Which ones? Only time will tell.

To say the least, Hutchins' ideas defy conventional wisdom of conservative, guild-style craftsmen, who contend that science has little to offer violin makers. As such, her strong will, tireless study, and what some call revolutionary approach to fiddle fashioning have made her a bit controversial.

Yet, after 40 years of meticulous research, the ideas of this 83-year-old independent experimenter have become so central to the craft that they may alter the future course of how stringed instruments are made.

"Her contribution in the long run will be very significant," predicts Joseph Curtin, a violin maker in Ann Arbor, Mich. "Her research is very interesting. She works in the gap between violin making and physics, caught between the two worlds. Sometimes, scientists treat her as a violin maker, and violin makers treat her as a scientist. Many of her instruments are done as controlled experiments to try out an idea."

Hutchins bought her first viola at age 37, making her achievements even more unusual. She built her first violin after bearing her first child, then learned acoustical physics from Frederick A. Saunders of Harvard University.

Hutchins' foremost idea bears the name "plate mode tuning." In essence, the theory holds that what makes for the smooth, sonorous sounds of a great instrument is the subtle, synergistic interaction of air vibrating inside a violin's body and the vibrations of its top and bottom wooden plates. The modes refer to specific vibrational patterns and frequencies. Together, these three vibrating bodies -- two plates (top and bottom) and the air in between -- interact to create a complex stream of sound.

In a primitive sense, one can think of a violin as an unsealed wooden box, strung with 60 pounds of force, that resonates when stroked with a bow. The motion of a bow dragged across those strings sets them vibrating. This causes the violin body to undulate rapidly, expanding and contracting some 400 times a second. Those vibrations move air, setting in motion sound waves that eventually tingle a listener's ears.

But understanding and controlling how those front and back plates vibrate is no simple matter. It's tough enough to know if they're moving in synchrony. Even trickier is controlling the frequencies and shifting the center of these vibrations to just the right spot, so the violin's front plate, back plate, and the air in between vibrate in harmony.

Hutchins focuses on the dynamics of those vibrations -- learning how to "tune" the top and bottom plates. When stroked by a bow, a violin in fact undergoes many different kinds of vibrations through its top and bottom, its neck, its fingerboard, and around the "f-shaped holes" cut into its top. One of Hutchins' more controversial theories holds that by adjusting a small difference in frequency between a particular pair of air and wood vibrations -- a difference she calls "the A1-B1 delta" -- one can critically alter the violin's tonal qualities.