Flatwound strings on fretless bass guitar

A string is the vibrating element that is the source of vibration in string instruments, such as the guitar, harp, piano, and members of the violin family. They are lengths of a flexible material kept under tension so that they may freely vibrate. Strings may be "plain" (consisting only of a single material, like steel, nylon, or gut) or they may have a core of one material with an overwinding of other materials to add mass so the string sounds the desired pitch, while keeping the string thin and flexible enough to play. Such strings are called "wound strings."

[edit] String construction

Depending on the construction of the instrument on which they are used, strings will usually have either a ball or loop at one end to attach the string to the instrument. Strings for some instruments may be wrapped with silk at their ends to protect the string. The color and pattern of the silk can be used to identify the string.

[edit] Winding

There are several varieties of wound strings.

[edit] Roundwound

The simplest strings are roundwound. They have either a round core or a hex core inside and round winding wire, wound in a tight spiral around it. Such strings are usually simple to manufacture and thus are usually the least expensive. There are several drawbacks, however:

• Roundwound strings have a surface profile (the "bumps" of the winding) that causes "squeaking" sounds when the player's fingers slide over the strings. Whereas some artists use this sound creatively on purpose, this sound is, in general, unwanted.
• Non-flat surface profile also hastens fingerboard and fret wire wear.
• When the core is round, the winding is not secured to the core and can rotate freely around it, especially if the winding is damaged after use.
  
  

[edit] Flatwound

Flatwound strings also have either a round core or a hex core, but the winding wire has a rounded square cross-section. When tightly wound, such strings have a much shallower profile (in cross-section), thus making them more comfortable to play, less damaging for frets and fretboards, and producing quieter squeak sounds from fingers sliding along the string. Flatwounds strings generally take much longer to go "dead", as they have fewer and smaller grooves for dirt/oil to build up in. However, players frequently cite that the sound of flatwound strings differs considerably from the sound of roundwound, with less brightness. Flatwounds also usually cost slightly more than roundwounds.^[1][2]

[edit] Halfwound, ground wound, pressure wound

Halfwound strings, ground wound strings or pressure wound strings are a cross between roundwound and flatwound, providing tonal characteristics somewhere between the two types, and have the lack of squeaking and the playing feel of flatwound. Such strings are usually made by winding round wire around a round or hex core first, then polishing, grinding (thus the name, ground wound) or pressing the exterior part of the winding until it is practically flat.

Note that the polishing process removes almost half of winding wire mass, thus, to compensate for it, manufacturers have to use heavier gauge winding wire.

[edit] Hexcore

Hexcore strings are composed of regular hexagonal core and a tight (usually round) winding. It solves a problem that round core strings have, of the winding slipping around the core. The hexagonal shape of the core creates six corners which secure the winding around the core better, so it cannot rotate and slip under the fingers.

[edit] Gauge

A wound acoustic guitar string (phosphor bronze wound around steel) with a ball end, 0.044" gauge

The tone of a string depends partly on its weight, and, therefore, on its diameter or so-called gauge. Traditionally, diameter is measured in thousandths of an inch (0.001 in = 0.0254 mm). The larger the diameter, the heavier the string is. Heavier strings require more tension for the same pitch and are, as a consequence, harder to press down to the fingerboard. If a fretted instrument is restrung with different string gauges, it may be necessary to adjust the height of the string above the frets, called the "action," in order to make the instrument easier to play or to avoid the strings buzzing against the frets. The action height of fretless instruments may also be adjusted to suit the string gauge or material, as well as the intended playing style.

Steel strings for 6-string guitar usually come in sets of matched strings. Sets are usually referenced either by the gauge of the first string (e.g., 9), or by pair of first and last (e.g., 9-42). Some manufacturers may have slightly different gauge sequences; the sample data below comes from D'Addario string charts for regular, round-wound, nickel-plated strings.

(Note: strings in dark gray boxes are wound. All others are plain.)

Typical bass guitar strings come in the following gauges. Bass guitar strings are sometimes made for a particular scale length and come in short, medium and long scale.

Note that some manufacturers of strings produce other sets of strings too; the figure above merely lists the most commonly used combinations.

Strings for violin family instruments are often sold in 3 gauges simply labeled heavy, medium, and light, which do not have a standard size associated with them. (These gauges are sometimes called by their German names, stark, mittel, and weich.)

[edit] Materials

[edit] Core

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Steel forms the core for almost all^[3] metal strings. Certain keyboard instruments (eg harpsichord) and the Gaelic harp use brass. Other natural materials such as silk or gut, or synthetics such as nylon and kevlar are also used for string cores. (Steel used for strings, called music wire, is hardened and tempered.) Some violin E strings are gold-plated in order to improve the tone quality.

Sheep and bull gut (called catgut, even though cats were never used for this purpose) were the original materials used as cores for strings for violin family instruments. Gut strings are subject to changes in humidity, which cause them go out of tune, and they also break more easily than other core materials. However, even after the introduction of metal and synthetic core materials, gut strings remain in widespread use because their warmer tone is preferable to some players. Modern gut strings are usually wrapped in metal. Nylgut strings are a recently developed alternative to gut strings - made from a plastic material, they offer almost exactly the same acoustic properties as gut strings, but with none of the problems of tuning caused by climatic variations. Many players of early music now use them in preference to genuine gut.

Silk was extensively used in China for traditional Chinese musical instruments until they were replaced by metal-nylon strings in the 1950s. Only the silk strings used for the guqin are still produced; the quality in ancient times was very high to the extent that there was a brand praised as 'ice strings' because of their smoothness and translucent appearance. ^[4]

At the present time, one of the most popular materials for the cores of violin, viola, cello, and bass strings is stranded nylon, often sold under the trade name of Perlon.

Nylon guitar strings were first developed by Albert Augustine Strings in 1947.^[5]

Today, most jazz and folk string players prefer steel-core strings for their faster response, low cost, and tuning stability, whereas most classical string players prefer synthetic-core strings (Perlon etc.) for their richer overtones and "warmer" tone.^{[citation needed]} Most baroque string players still prefer gut-core strings.

By far the most popular string combination for a modern concert violinist is synthetic-core G, D, and A strings, with a steel E string.^{[citation needed]}

[edit] Winding

Aluminum is the most common for bowed instruments like violin and viola, whereas acoustic guitar and piano strings are usually wound with bronze, and bass guitar strings most commonly in stainless steel or nickel^{[citation needed]}. Copper, gold, silver, and tungsten are also used. Silver and gold are more expensive, and are used for their resistance to corrosion and hypoallergenicity.

Some "historically-informed" strings use an open metal winding with a "barber pole" appearance.

"Silk and steel" guitar strings are overwound steel strings with silk filaments running under the winding.

[edit] String vibration

A string vibrates in a complex harmonic pattern. Every time a string is set into motion, a specific set of frequencies resonate based on the harmonic series. The fundamental frequency is the lowest (and loudest), and it is determined by the density, length and tension of the string. This is the frequency that we identify as the pitch of the string. Above that frequency, overtones (or harmonics) are heard, each one getting quieter the higher it is. For example, if the fundamental pitch is 440 Hz (A above middle C), then the overtones for a string tuned to that pitch will be 880 Hz, 1320 Hz, 1760 Hz, 2200 Hz, etc. The note names for those pitches would be A, A, E, A, C#, etc. Due to the mass of the strings, however, the higher up the overtones go, the more out of tune (or "false") they are to the fundamental. This is an important consideration for piano tuners, who try to stretch the tuning across the piano to keep overtones more in tune as they go up the keyboard.

[edit] String corrosion

Metal strings offer a unique problem, as they are susceptible to oxidation and corrosion. Wound strings that use metals such as brass or bronze in their winding will eventually corrode, as moisture and salts from the player's fingers build up oxides on the string. As a result, the string will lose its brilliance over time.^[6] To help solve this problem, string manufacturers apply a metal plating or polymer coating to protect the string from corrosion.

[edit] See also

• Violin construction and mechanics
• Electronic tuner

[edit] References

[edit] External links

• Identify strings by their silk patterns
• The vibrations of strings with both ends fixed
• Guitar Strings From The Nineteenth Century To The Advent Of Nylon
• Historical types of string
• String Calculation; String Measurement; Mass Per Unit Length
• Custom String Gauge Design Terry Downs
• String Tension - technical information on string tension, with tension calculator