String Theory

Ever wonder how firms develop the latest strings? In 2004, Strings enlisted James Keough to find out

Everyone in the stringed-instrument field agrees on one thing: The perfect string does not exist. Players and string manufacturers alike say the instruments, playing styles, and the demands of the repertoire vary way too much for a one-string-fits-all approach. Pirastro Strings’ Annette Müller-Zierach succinctly states the case: “We do not believe that one individual string can suit every instrument and can be regarded as a standard. If this has happened in the past, it was simply a matter of lack of choice.”

In string making the past belongs to gut and gut alone, and for some, that makes gut the gold standard. But steel strings forced a toe in the door in the early 20th century, and nylon-core strings made their debut in the 1970s. Since then, string manufacturers have continuously adapted new technology to the age-old processes of string making. Nowadays lack of choice no longer applies. In fact, having lots of options has lead some players on a never-ending search for the musical equivalent of the Holy Grail. It’s a quest longtime cellist Terry King still pursues: “I keep experimenting and changing brands. The differences are subtle and I think reflect a changing aesthetic rather than an ‘improvement’ over the old string brand. These preferences are of a certain attraction in sound that I think reflects my current taste. Nothing wildly saying, ‘Now this is the string I’ll use forever.’”

Similarly, cellist Sarah Freiberg admits, “I like to experiment . . . . I keep feeling there must be something better out there.”

One could, of course, write off such striving as merely part of being a cellist. After all, as Freiberg affirms, “cellists can never find a full set of strings to work well on their instruments.” But having a wide range of choices has even begun to affect the more steadfast violinists, who have typically not only stuck to one brand but have often played full sets by that manufacturer.

Fan-Chia Tao, head of research and development at D’Addario & Co., sees even that changing and predicts that mixing and matching strings will only accelerate. “If [violinists] are confronted with more choices and they’re more educated about the possibilities of using strings to modulate or affect their sound or response,” he says, “I think they’ll be willing to experiment more.”

The More Things Change . . .

Of course, many players have always customized their strings, picking and choosing among brands and the three different tensions—low, medium, or high—that manufacturers typically provide. Fritz Gearhart, violinist with the Oregon String Quartet who now experiments with various synthetic-core strings, says for years he used “a specific combination, [Dominant] Stark G, Silver D, [Regular] A, and a Gold Label E string.”

And manufacturers have responded. Thomastik-Infeld, for instance, introduced its Infeld Red and Blue strings, which offer “darker” and “brighter” alternatives of the same type of string.

Despite all the advances in string manufacturing in the past 25 years or so, on one level not that much has changed. As D’Addario’s Tao quickly points out, “modern strings are basically made the same way they were 300 years ago, conceptually. The only difference is that today we use a much larger variety of materials.”

Except for most violin E strings and some pure gut strings, all modern strings share the same basic construction: a gut, synthetic, or stranded-steel core, often covered by some form of damping material, wound with ribbons of metal. String makers added metal windings some 300–400 years ago because they could make these gut-core strings thinner than pure gut, especially the lower strings, and, therefore, easier to play. “Lower strings generally have more windings,” Tao says. “Typical violin strings have two windings, viola C strings have three windings, cello C strings as many as four windings, and the low bass strings, even five windings.”

Whether made by hand or on a computer-controlled winding machine, Tao explains, all wound strings undergo the same process: a knot, loop, or ball is attached to one end of the core and the core is placed on a lathe-like machine and properly tensioned. As the core rotates the machine winds a thin ribbon of wire uniformly around it. After the proper number of windings are applied, the string is polished smooth with sandpaper and the ends are wrapped with thread to keep them from fraying and to provide additional friction at the peg end.

Gut Feeling

While no one misses the downside of gut strings—their fragility, the fact that they take a long time to break in, their sensitivity to changes in humidity, and their resultant instability—many players and string manufacturers still hold the sound gut produces as the benchmark for synthetic strings.

“High-quality gut strings have the widest range of overtones and have a sweet, rich, brilliant but at the same time warm tone,” says Pirastro’s Müller-Zierach, whose company has produced gut strings since 1798 but also makes synthetic-core strings. And it’s a sound she doesn’t think manufacturers will be able to reproduce in the near future with a synthetic core because “the compact protein structure of raw gut cannot be compared with the molecular structure of a synthetic multifilament.”

Fan-Chia Tao, who distinguishes between modern gut strings, which incorporate advances in sheathing and winding technology, and traditional, simply wound gut strings, agrees: “So far nobody has really figured out a way of making modern nongut strings behave and sound completely like gut strings.”

Even so, Tao thinks the reverence afforded gut strings stems partly from what he calls “mythological reasons. . . very few people actually know what a gut string truly sounds like because now very few people have ever played them.”

Helmut Frank, Thomastik-Infeld’s marketing director, shares Tao’s skepticism when he says that “certain players who are looking for the original sound—whatever this might be—will always use gut strings,” but he quickly debunks the gut-as-benchmark nostrum. “Listening habits of players and audiences have changed significantly over the years,” he says. “Everybody is going for bright, clear, defined sound—exactly the opposite of gut sound!”

Still, the “historical” sound produced by gut strings exerts tremendous influence on string manufacturers. “All Baroque, Classical, Romantic, and even most 20th-century music has been written with the ‘gut sound’ in mind,” says Morten Drasbek of Larsen Strings, makers of steel-core cello strings. “Hence it cannot be disregarded.

“At the same time, music is always on the move, and while we like to retain the best of the past, we like to combine it with the best of the present and the future.”

A number of larger manufacturers continue to produce gut strings and continue to invest in gut-string R&D, but Philippe Durand, Product Manager at Corellisays, “Considering that gut is a natural material, it seems difficult to discover new improvements.”

For Durand, “new developments are to be expected more in the windings.” Like most other gut-string manufacturers, Corelli also makes synthetic-core strings using a new composite substance called Alliance KF.

Most of the innovation in gut-string technology might more accurately be called re-innovation, and it is occurring in boutique string shops like Gamut Strings, headed by Daniel Larson. He’s been making traditional gut strings for the period-instrument market for about 25 years and has steadily improved the quality of his strings by returning as much as possible to historical methods.

“It’s been a process of trying to develop a gut string that more or less mimics the comments people were making historically and the few examples of historical strings that we have,” he says.

Larson sees his market growing even as the modern gut-string market steadily shrinks, and, of course, he thinks gut strings often get a bum rap for being fragile and temperamental: “Generally speaking, I think gut strings are as stable as any string if they are gauged properly, and the tension and the string length and everything is right with the pitch they’re supposed to be playing at.” He hasn’t, alas, been able to find a way around the higher price of gut strings. “Gut is a world commodity and it’s traded on the world market,” Larson says, “so when they have a drought in Australia it really does affect the cost of a string that’s played in Carnegie Hall.”

Targeted Approach

The search for a more stable substitute for gut began with steel wire, but it really hit its stride when Thomastik-Infeld introduced its aptly named Dominant nylon-core strings some 35 years ago. Where the early steel strings produced a bright, somewhat brittle sound that most violinists found unsatisfactory, the multithread nylon-core strings approximated the warmth and playability of gut, and their strength and stability proved a vast improvement over the natural material.

As Tao points out, “It was very commonplace that . . . one out of a certain number of gut strings you just took for granted would have terrible problems. You’d just have to toss it in the trash when you put it on.” And that, he says, no longer happens with modern synthetic- or steel-core strings.

But strength and stability—you’ll forgive the phrase—play second fiddle to such musical issues as tone and playability. Super-strong space-age materials may offer great promise as core materials for strings, but as Tao says with a smile, “the qualities you want for bulletproof vests are not necessarily the qualities you want for strings.”

While string manufacturers continually test the density, elasticity, and potential sound properties of all manner of raw materials with ever more sophisticated laboratory equipment, they do so because they want to solve musical problems.

“Rather than focus on such and such raw material, we look for the string’s characteristic and check for the material that can help us to reach our target with the best result,” says Corelli’s Durand.

Tao says D’Addario takes a similar approach. “We’re trying to design and market strings on the basis of what they sound like and what they do for the player and what type of result [the player] can expect to get,” he says, “rather than what is the material and the technology that’s used to make the product.”

As an example, he touts D’Addario’s Kaplan Solution strings, which he says “were designed to address very specific problems, the [need for a] nonwhistling violin E string, and [for a] viola A string . . . to address the issue of a much more projecting A string.”

Pirastro has likewise addressed the whistling E-string problem with its No. 1 Universal E string. The new materials available for string cores and windings provide manufacturers opportunities to explore two critical factors in string performance, damping and density. According to Tao, damping plays an important role in determining how a string sounds, “how bright it is versus how dull” it sounds.

“The traditional material, gut,” he says, “has very high damping, which means the sound dies away very quickly. A string that dies away quickly also starts up much quicker. Most synthetics and steel have very low damping, and they tend to be more like guitar strings than gut strings, so we put in additional damping materials.”

Damping is especially important for steel-core strings, which without it sound “bright and harsh,” according to Durand. String manufacturers readily admit to incorporating damping technology in their strings—they just won’t say how.

“All manufacturers have their little secrets to add damping to a string,” says Frank, typically by “using soft layers of synthetic materials, which absorb the energy induced into the string by bowing.”

String density also affects tone, making the string sound “darker” as density increases. Density is primarily a factor of the winding material rather than the core—winding gut strings with metal revolutionized string making three or four centuries ago by effectively increasing the string’s mass without increasing its diameter—and the relative density of the winding material impacts the string’s playability as well as its tone.

Silver and copper wire, the original windings for gut strings, are still used effectively as are nickel, aluminum, and steel, but more exotic materials, such as tungsten and titanium, though expensive, have found increasing favor.

Almost twice as dense as silver, which itself is roughly three times as dense as aluminum, tungsten allows string manufacturers to make a thinner string that still has a big, full sound.

“That’s why it’s used on the lower strings, viola C and cello C, and sometimes G string,” says Tao. “Smaller diameter strings are easier to play and are more responsive.”

Titanium, while not as dense as tungsten—it’s somewhere between aluminum and copper and silver—is by far the hardest and most corrosion-resistant metal used in string making, and because of these two qualities it often replaces aluminum as the winding on certain upper strings. According to Frank, “Titanium is a big leap forward in string design,” and R&D engineers are using its “very special specs to try to solve string problems that could not be worked around that easily [using other materials].”

But while some trumpet titanium as the be-all and end-all material for string winding (as it is being hyped in everything from golf clubs to razor blades), others adopt a more moderate stance. Pirastro has used titanium since 1997, but because it’s so expensive and so hard to work with, as Müller-Zierach explains, “In our opinion it should only be used where it provides a substantial advantage that no other material can provide.”String engineers love to talk about all the exciting new developments in the offing, and there’s no question that computer-driven technology will play an even larger role in string development.

But with that truism comes the simple caveat that no matter how sophisticated the technology gets, string making is still an art. “Most string research makes use of signal processing, frequency analysis, huge computer power, material research, psychoacoustics, and so on,” says Helmut Frank, “but at the end of the day we sit down with Mistislav Rostropovich, Pinchas Zukerman, and Itzhak Perlman to get real feedback.”

Terms of Endearment

The proliferation of materials and tensions available to string players has forced string makers’ marketing departments to work overtime describing the sound their strings produce.

As Gamut Strings’ Daniel Larson observes, “It used to be when you looked at a catalog description of synthetic-core strings it would say ‘sounds like gut but will stay in tune.’”

Nowadays they read more like a wine taster’s description of a fine Cabernet, with terms like “dark,” “rich,” “brilliant,” “clear,” and “round” bandied about in multiple combinations.

These terms are clearly meant to be evocative, but they often create problems for the consumer looking for an objective way to categorize strings and the sound they produce. In part this occurs because the objective differences between what Müller-Zierach calls the “sound pictures of individual strings” are very small.

“Even the worst violin still sounds like a violin and not a trumpet,” says Tao, “but subjectively, of course, within the sphere of all violins and all strings we make a big deal of small differences.”

Tao says he tries to avoid absolutes: “I want to steer people to comparisons, ‘Is this brighter than that?’”

Similarly, Müller-Zierach says Pirastro’s “aim is to provide guidelines by comparing our strings with each other.”

But Tao thinks the manufacturers need to do a better job describing what their strings do so they can better help the consumer select strings to match their instruments.

“So if you have a bright instrument and you want a warmer sound,” he says, “use this particular string. Our Xyex strings have a warmer sound than the Dominant—not better, just warmer.”

Metal Urgency

The earliest undisputed evidence of metal-wound strings dates from the late 17th century, about the time of Stradivari, when string makers began using silver and copper wire to add density to gut strings.

Since then string makers have added gold, bronze, steel, aluminum, tungsten, and, most recently, titanium to their winding repertoire.

Each of these metals has specific applications, depending primarily on their individual densities, but also on their strength, ability to resist corrosion, their workability, and, of course, their cost.

Silver, for instance, is relatively expensive, so it is seldom used as an interior winding; copper, which is relatively cheap, is rarely used as an exterior winding because it corrodes easily.

According to Annette Müller-Zierach, managing director at Pirastro, “Every metal has certain physical properties, which allows a different construction of a string and hence a different sound.

It is possible to say, for example, that an Obligato violin D string wound with aluminum will be considered warmer sounding than the same string wound with silver.

In general it is also true to say that metals such as aluminum and silver are warmer sounding than chrome steel or nickel.”

But before you get, ahem, all wound up about which type of metal string imparts which kind of sound, bear in mind that the type of metal used as the final winding isn’t the only thing contributing to the sound a string produces.

“The actual construction and geometry of a string affects the sound much more than the metal used in the windings,” says Fan-Chia Tao, director of R&D at J. D’Addario.

“The identified metal is usually the outer wrap, and the insides can be very different. There are dull nickel strings and bright aluminum strings, so I tell our customers the construction of the string is much more important than the metal used [in the wrapping].”

This article appeared in the December 2004 issue of Strings.