Steel forms the core of most metal strings. Certain keyboard instruments (e.g., 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 to improve tone quality.
Steel Steel or metal strings have become the foundation of strings for the electric guitar and bass. They have a pleasingly bright tone when compared to nylon strung guitars. Their metal composition varies greatly, sometimes using many different alloys as plating. Much of the history of metal strings evolved through innovations with the piano. In fact, the first wound metal strings ever used were used in a piano. However, when it came to getting super small diameter strings with good elastic properties, the electric guitar took the metal string to the next level adapting it for the use of pickups. Because of the higher tension of steel strings, steel-strung guitars are more robustly made than 'classical' guitars, which use synthetic strings. Most jazz and folk string players prefer steel-core strings for their faster response, low cost, and tuning stability.
Nylon Nylon (typically 610 or 612) string, traditionally used for
classical music, has a more mellow tone, and the responsiveness of it can be enjoyed typically for folk but other styles of music use it as well (for example,
Willie Nelson performs on a nylon strung guitar). Nylon is a softer, less dense material and nylon strings are used with about 50% less tension than steel strings. This means they can be used on older guitars that can't support the tension of modern steel strings. Nylon strings do not work with
magnetic pickups, which require
ferrous strings that can interact with the magnetic field of the pickups to produce a signal. Currently, stranded nylon is one of the most popular materials for the cores of violin, viola, cello, and double bass strings. It is often sold under the trade name of
Perlon. Nylon guitar strings were first developed by
Albert Augustine Strings in 1947.
Gut The
intestine, or gut, of sheep, cattle, and other animals (sometimes called
catgut, though cats were never used as a source for this material) is one of the first materials used to make musical strings. In fact, the Ancient Greek word for string, "khordḗ," has "gut" as its original meaning. Animal intestines are composed largely of
elastomers, making them very flexible. But they are also extremely hygroscopic, which makes them susceptible to pitch fluctuation as a result of changing humidity. Exposure to moisture from the sweat of a musician's hands can cause plain (unwound) gut strings to fray and eventually break. This is not as much of a problem with wound gut strings, in which the gut core, being protected from contact with perspiration by the metal winding (and underlayer, if there is one), lasts a much longer time. All gut strings are vulnerable to going out of tune due to changes in
atmospheric humidity and as a gut string ages and responds to cyclic changes in temperature and humidity the core becomes weak and brittle and eventually breaks. However, despite the introduction of metal and synthetic core materials, many musicians still prefer to use gut strings, believing that they provide a superior tone. Players associated with the
period performance movement use wound and unwound gut strings as part of an effort to recreate the sound of music of the Classical, Baroque, and Renaissance periods, as listeners would have heard it at the time of composition. For players of plucked instruments, Nylgut strings are a recently developed alternative to gut strings. They are made from a specialty nylon and purport to offer the same acoustic properties as gut strings without the tuning problems.
Fluoropolymers (aka "Carbon") Fluoropolymer strings are available for classical guitar, harp, and ukulele. This is the same material used for
monofilament fishing lines, and a typical chemical used is
PVDF. These strings are usually traded under descriptions like
fluorocarbon,
carbon fiber, or
carbon, which is scientifically incorrect. The so-called
Carbon material has a higher
density than nylon, so that a nylon string can be replaced by a carbon string of smaller diameter. This improves the precision of higher fretted notes, and the resulting vibrational behaviour leads to a more brilliant sound with improved
harmonics. In particular,
classical guitarists who feel that a nylon G string sounds too dull can use strings that include a carbon G string.
Other polymers Other polymers, including
polyetheretherketone and
polybutylene terephthalate, have also been used.
Silk Silk was extensively used in China for
traditional Chinese musical instruments until replaced by metal and nylon strings in the 1950s. Only purely silk strings used for the
guqin are still produced, while some silver-wound silk strings are still available for classical guitars and ukuleles. The quality in ancient times was high enough that one brand was praised as 'ice strings' for their smoothness and translucent appearance. == Winding materials ==