String Theory: New Approaches to Instrument Design

[alocispepraluger102]

November 28, 2006

String Theory: New Approaches to Instrument Design

By ANDREW C. REVKIN

“I think best in foam,” Douglas Martin said as he sorted through a heap of pink violin-shaped slabs in the kitchen-cum-workshop of his snug colonial house in southern Maine.

Each piece of foam was a template for an experimental instrument he had built or was preparing to build, but none used the traditional spruce and maple favored through most of the hallowed 500-year history of the violin.

Mr. Martin, 63, whose day job is designing sleek rowing shells that slice through ocean surf, is consumed in spare moments by a similarly unorthodox pursuit: abandoning age-old norms of acoustic instrument design as he chases his conception of the ideal violin sound.

A dining table was strewn with rough-hewn violins built of balsa wood and graphite fibers, some with the standard instrument’s familiar curves and narrow waist, but others boxy and ribbed, as if they had been built inside out.

In art school in the 1960s, a professor once tossed one of Mr. Martin’s sketches on the floor and scuffed it up, urging him to abandon caution, and he clearly absorbed that notion.

When a violinist tried an instrument at a recent workshop and one of its blunt shoulders got in the way of his wrist, Mr. Martin summarily sawed off the corner and sealed the opening with a scrap.

He might be mistaken for an eccentric dabbler, except that he is far from alone. From Australia to Germany to Maui, there is something of an explosion under way in the use of science and new materials to test the limits of instrument making.

And the traditional violin-making and violin-playing world is taking note.

Last year, Mr. Martin passed around one prototype, Balsa 4, at an annual workshop on violin design at Oberlin College by the Violin Society of America, a group of builders. When it was played and run through an array of tests, the instrument’s responsiveness and punch startled the gathering, several participants said.

Joseph Curtin, a director of the workshop and a builder from Ann Arbor, Mich., who received a 2005 MacArthur Foundation “genius award” for his violin designs, wrote about Mr. Martin’s work in the society’s newsletter, saying “the traditional violin became obsolete in early July of 2005.”

In an interview, Mr. Curtin said that was only partly a playful exaggeration. It will be a long time before balsa and graphite become the materials of choice, he said. But he added that Mr. Martin and other experimenters were legitimately challenging longstanding notions of what makes a great acoustic instrument, and whether past masters’ work represents a sonic pinnacle or merely the best that could be achieved with traditional materials.

Some of the new designs are mass-produced, with companies (many founded by former aerospace engineers) turning out hundreds of synthetic weatherproof guitars and instruments in the fiddle family.

Others, like Mr. Martin’s, are one-off prototypes. (He has sold only three.)

In almost every case, a central goal, particularly in the resonating top or soundboard most responsible for an instrument’s voice, is a mix of stiffness and lightness.

This combination increases an instrument’s ability to turn the energy in a vibrated string into waves of appealing sound.

That is where unconventional materials come into play. Layered graphite fibers and carved balsa are very stiff but far less dense than the traditional choice of spruce.

“Wood reached the limits of its potential in the first half of the 18th century,” Martin Schleske, a leading violin maker from Munich, asserted in a recent lecture in Germany. “I have no doubt that if Stradivari were alive today with the same force of innovation, he would have already discovered the fascinating acoustic properties of graphite fibers and would have ushered us into a new golden age of violin making.”

This month, Ingolf Turban, a touring concert violinist, compared Mr. Schleske’s latest violin, which has a top made of a mix of spruce and graphite, with a 1721 Stradivarius by recording passages from Mozart’s Violin Concerto in D Major with each. He told Mr. Schleske he preferred the new one.

“I have never been playing any violin with such a singing E string,” Mr. Turban said in a testimonial. “It is no longer like playing violin but like singing.”

Some instrument makers and researchers are using science to deconstruct the dozens of kinds of vibrations and waves that interplay in a violin or guitar to create their distinctive sounds.

Working with Mr. Curtin and several other violin makers, George Bissinger, a physicist at East Carolina University in Greenville, N.C., is using medical-imaging gear, laser scanners, arrays of microphones and computers to measure and model how the parts of a violin react once energy is introduced by a bow, fingertip, pick or, in the laboratory, the repeated taps of a tiny hammer.

Depending on many interrelated variables, from the force exerted on the strings by the player to the stiffness, density and shape of an instrument’s parts, a layered field of sound emanates, sometimes containing dozens of distinctive overtones and harmonics.

Some sounds disperse in the air evenly in all directions, while others — especially high notes on a violin — push outward in a particular direction, funneled by the shape of the instrument.

Particularly important, Dr. Bissinger said, is determining which factors translate the side-to-side sawing of a bow on a string into vertical motions of the violin top. “Up and down is what matters,” he said.

Other vibrations travel in the body — at different speeds reflecting the orientation of wood grain — setting up all manner of ripples and bouncing waves and more ripples.

In instruments built entirely of meshed graphite fibers, the vibrations move uniformly, offering both challenges and opportunities to instrument makers.

Another important influence, particularly on low violin notes, is the movement of air in and out of the f-holes, Dr. Bissinger said. If the dimensions are right, the air sloshes forward and back like disturbed water in a bathtub (or air in an organ’s pipes) at rates that increase the instrument’s volume.

The materials in the body matter because they determine how much of the energy imparted to an instrument moves into the surrounding air as sound and how much is dissipated as heat within the matrix of molecules that make up the instrument’s body.

That damping effect is not all bad, guitar and violin makers say, and may be one of the characteristics that give a mellow tone to older instruments in contrast to the almost metallic brightness sometimes heard in new ones.

In September, Dr. Bissinger ran three days of tests on two violins built by Stradivari and one by Guarneri del Gesù — worth a combined $14 million or so — as well as instruments by Mr. Curtin and Sam Zygmuntowicz, a violin maker from Brooklyn.

By comparing the response of the legendary instruments to the new ones, and to data from a batch of bad student violins, Dr. Bissinger said, he is trying to develop an anatomical guide of sorts, revealing which features determine the qualities of which parts of a violin’s sound, from the lowest notes to the highest trills.

“I like the bad ones as much as the good,” he said. “How can you know beautiful if you don’t know ugly?”

Dr. Bissinger said that the experiments with balsa and carbon were clearly helping expand understanding of the boundaries of violin sound, but that they have “a tall hill to climb” to compete in the marketplace with traditional instruments, which have already shown their ability to last 300 years and hold up to the pounding of a Paganini solo.

At the University of New South Wales in Sydney, Australia, another physicist, Joe Wolfe, has assembled a team that is testing whether an instrument’s age or the amount it has been played change its sound.

In interviews, instrument players and dealers expressed a conviction that vintage does matter, and several theories have been proposed for how aging changes the structure of wood in ways that affect sound.

But Dr. Wolfe and Ra Inta, another member of the Australian team, said that rigorous experimental evidence was scant, with a couple of recent studies, for example, offering conflicting findings.

They have a long-term study under way on two identical violins built by a local maker, Harry Vatiliotis, from the same 80-year-old slabs of spruce and maple. One is sitting nearly untouched in a museum and the other is in constant use in the hands of a concert violinist. But it will be many years before enough time has passed to determine if all those vibrations from continual bowing have altered the wood in substantive ways, the researchers said.

Such scientific analysis has produced some trepidation among traditionalists, Mr. Curtin said. “There’s a kind of a nervousness that the mystery will go out of it, the bubble will be pricked and it’ll all just be ordinary. It’ll be technology. There’s almost a cultural sense that the violin is the last repository of mystery. The fact that we don’t understand the violin adds to its allure.”

Mr. Curtin, who is also experimenting with balsa but is laminating a thin veneer of tougher spruce on top, said such fears were unfounded. “To me, understanding always makes things more interesting, not less. That’s been true for biology. I think it’s the same with acoustics.”

The work on new materials is driven variously by simple passion and curiosity, as in Mr. Martin’s case, and commerce, as companies hunt for ways to make better mass-produced instruments. (Student violins are notoriously hard to play, discouraging learners just when they should be inspired.)

Another goal propelling some builders toward synthetic materials is the prospect of creating fine-sounding instruments that can endure abuse and the vagaries of weather that can destroy an old wood model.

John A. Decker Jr., a physicist and aeronautical engineer, created his weatherproof and resonant RainSong line of all-graphite guitars after moving to Maui in 1981 to manage an Air Force observatory. He found that the extreme Hawaiian humidity and heat ravaged his classical instruments.

The top guitars, with nary a fleck of wood in sight, sell for more than $2,000 and have showed up in the hands of performers including two longtime rockers, Steve Miller and Daryl Hall. Dr. Decker said the most responsive possible guitar soundboard would be one with infinite stiffness and zero mass, so that the energy from the slightest tug of a finger on a string would translate most efficiently into moving air instead of diffusing as heat in the structure of the instrument.

Graphite fibers allow the top to be pared to the minimum mass and eliminate the need for supporting braces required in conventional wooden guitars, he said.

He said there were always trade-offs, and aesthetics is surely one. “Graphite is not a very romantic material,” said Dr. Decker, who builds wooden classical guitars in spare hours. “It doesn’t have grain and swirl and flame and all the things that koa and quilted mahogany do. On the other hand, you know what the thing is going to sound like, which from the musician’s point of view is better.”

For Mr. Martin, the experimentation is ultimately driven by his search for a sound: a soaring, enveloping sound he recalls vividly from childhood summer nights around a campfire in Cohasset, Mass., when a friend’s dad pulled out an old Italian violin.

“The sound of that instrument just burned in my brain,” Mr. Martin said.

As of last weekend, he was still in pursuit, having just started on Balsa 15, with no end in sight.

Copyright 2006 The New York Times Company

[7/4]

I already posted this yesterday, in the musician's forum.

Edited November 29, 2006 by 7/4

[alocispepraluger102]

I already posted this yesterday, in the musician's forum.

my apologies