String (music)
A string is the vibrating element which 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 or nylon), or they may have a core of one material with an overwinding of other materials to increase their mass and thickness. Such strings are called "wound strings."
String construction
Depending on the construction of the instrument they are used on, 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.
The tone of a string depends on its weight, and, therefore, on its diameter or so-called gauge. Traditionally, diameter is measured in thousandths of an inch, although, metric units are also used. The larger the diameter, the heavier the string is. Heavier strings require more tension for the same pitch and are consequently harder to press down to the fingerboard. Heavier strings will also produce a louder and thicker tone. (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. To a lesser extent, unfretted instruments may also need this adjustment.)
Steel strings for 6-string guitar usually come in the 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). Gauges are given either in inches or millimeters. 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 gray boxes are wound. All others are plain.)
| Name | 1 (e) in/mm |
2 (B) in/mm |
3 (G) in/mm |
4 (D) in/mm |
5 (A) in/mm |
6 (E) in/mm |
|---|---|---|---|---|---|---|
| Extra super light (8-38/20-97) | .008/0.20 | .010/0.25 | .015/0.38 | .021/0.53 | .030/0.76 | .038/0.97 |
| Super light (9-42/23-107) | .009/0.23 | .011/0.28 | .016/0.41 | .024/0.61 | .032/0.81 | .042/1.07 |
| Regular light (10-46/25-117) | .010/0.25 | .013/0.33 | .017/0.43 | .026/0.66 | .036/0.91 | .046/1.17 |
| Extra light w/heavy bass (9-46/23-117) | .009/0.23 | .013/0.33 | .021/0.53 | .029/0.74 | .036/0.91 | .046/1.17 |
| Medium (11-49/28-124) | .011/0.28 | .014/0.36 | .018/0.46 | .028/0.71 | .038/0.97 | .049/1.24 |
| Medium w/wound G string (11-52/28-132) | .011/0.28 | .013/0.33 | .020/0.51 | .030/0.76 | .042/1.07 | .052/1.32 |
| Heavy (12-54/30-137) | .012/0.30 | .016/0.41 | .020/0.51 | .032/0.81 | .042/1.07 | .054/1.37 |
| Extra heavy (13-62/33-157) | .013/0.33 | .017/0.43 | .026/0.66 | .036/0.91 | .046/1.17 | .056/1.57 |
Typical bass guitar strings come in the following gauges. Note that additional strings (5th and 6th) are usually sold separately. Bass guitar strings are sometimes made for a particular scale length and come in short, medium and long scale.
| Name | 1 (G) in/mm |
2 (D) in/mm |
3 (A) in/mm |
4 (E) in/mm |
5 (B) in/mm |
|---|---|---|---|---|---|
| Light (40-100/102-254) | .040/1.02 | .060/1.52 | .080/2.03 | .100/2.54 | .130/3.30 |
| Medium (45-105/114-267) | .045/1.14 | .065/1.65 | .085/2.16 | .105/2.67 | .130/3.30 |
Core materials
Steel forms the core for almost all[1] metal strings; 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 was used for a long time as strings for violin family instruments. Gut strings are very prone to weather and humidity change effects and go out of tune often, also breaking easily. After the introduction of other string materials, metal and synthetic, gut strings remain in production because their warmer tone (with more complex overtones) continues to be desirable to some players. Modern gut strings are usually wrapped in metal.
Today one of the most popular materials for the core of violin, viola, cello and bass strings is stranded nylon often sold under the trade name of "Perlon". First introduced by Thomastik in the 1970s and 80s,[citation needed] synthetic strings are now widely manufactured.
Today, most jazz and folk string players prefer steel-core strings for their faster response, low cost and tuning stability, while 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 stings.
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.
Winding materials
Aluminum is the most common for bowed instruments like violin and viola, while guitar and piano strings are usually wound with bronze; copper, chrome, nickel, silver, and gold are also used. Although silver and gold are more expensive, but are used for their resistance to corrosion and hypoallergenicity.
Strings wound with round wire are called round wound; those wound with flat wire (giving a smoother surface) are called flatwound. There is also a winding type called "ground round", where the winding is ground flat to an even smoother finish; these are only used as electric bass strings.
"Silk and steel" guitar strings are overwound steel strings with silk filaments running under the winding.
Tungsten, an especially heavy material, is also used in string windings.
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 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. See Vibrating string for a fuller technical treatment.