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Guitar

Classification	String instrument (plucked, nylon stringed guitars usually played with fingerpicking, and steel-, etc. usually with a pick.)
Playing range
(a regularly tuned guitar)
Related instruments
Bowed and plucked string instruments

The guitar is a musical instrument with ancient roots, used in a wide variety of musical styles, and it is also a solo classical instrument. It is most recognized as the primary instrument in blues, country, flamenco, rock music and many forms of pop. The guitar usually has six strings, but four-, seven-, eight-, ten-, and Twelve string guitars also exist. Guitars are made and repaired by luthiers. Guitars may be played acoustically or they may rely on an amplifier that usually allows for electronic manipulation of tone. The electric guitar was introduced in the 20th century, and had a profound influence on popular culture.

History

Instruments similar to the guitar have been popular for at least 5,000 years. The guitar appears to be derived from earlier instruments known in ancient central Asia as the Sitara. Instruments very similar to the guitar appear in ancient carvings and statues recovered from the old Iranian capitol of Susa. The modern word, guitar, was adopted into English from Spanish guitarra, derived from earlier Greek word kithara. Prospective sources for various names of musical instruments that guitar could be derived from appear to be a combination of two Indo-European roots: guit-, similar to Sanskrit sangeet meaning "music", and -tar a widely attested root meaning "chord" or "string".

The word guitar is a Persian loanword to Iberian Arabic. The word qitara is an Arabic name for various members of the lute family that preceded the Western guitar. The name guitarra was introduced into Spanish when such instruments were brought into Iberia by the Moors after the 10th century. (See related article).

The Spanish vihuela "de mano" appears to be an aberration in the transition of the renaissance guitar to the modern guitar. It had lute-style tuning and a guitar-like body. Its construction had as much in common with the modern guitar as with its contemporary four-course renaissance guitar. The vihuela enjoyed only a short period of popularity, the last surviving publication of music for the instrument appeared in 1576. It is not clear whether it represented a transitional form or was simply a design that combined features of the Arabic oud and the European lute. In favor of the latter view, the reshaping of the vihuela into a guitar-like form can be seen as a strategy of differentiating the European lute visually from the Moorish oud. (See the article on the lute for further history.) The Ancient Iranian lute, called tar in Persian also is found in the word guitar. The tar is thousands of years old, and could be found in 2, 3, 5, and 6 string variations.

The Vinaccia family of luthiers is known for developing the mandolin, and may have built the earliest extant six string guitar. Gaetano Vinaccia (1759 - after 1831) has his signature on the label of a guitar built in Naples, Italy for six strings with the date of 1779 . This guitar has been examined and does not show tell-tale signs of modifications from a double-course guitar. However, fakes are common for guitars and their labels in this era, and caution should be taken.

Modern dimensions of the classical instrument were established by Antonio Torres Jurado (1817-1892), working in Seville in the 1850's. Torres and Louise Panormo of London (active 1820s-1840s) were both responsible for demonstrating the superiority of fan strutting over transverse table bracing.

The electric guitar was patented by George Beauchamp in 1936. Beauchamp co-founded Rickenbacher which used the horseshoe-magnet pickup. However, it was Danelectro that first produced electric guitars for the wider public. Danelectro also pioneered tube amp technology.

Types of Guitar

Guitars can be divided into two broad categories, acoustic and electric:

Acoustic guitars

An acoustic guitar is not dependent on any external device for amplification. The shape and resonance of the guitar itself creates acoustic amplification. However, the unamplified guitar is not a loud instrument. It cannot compete with other instruments commonly found in bands and orchestras, in terms of sheer audible volume. Many acoustic guitars are available today with built-in electronics and power to enable amplification.

There are several subcategories within the acoustic guitar group: steel string guitars, which includes the flat top, or "folk" guitar, the closely related twelve string guitar, and the arch top guitar. A recent arrival in the acoustic guitar group is the acoustic bass guitar, similar in tuning to the electric bass.

• Renaissance and Baroque guitars: These are the gracile ancestors of the modern classical guitar. They are substantially smaller and more delicate than the classical guitar, and generate a much quieter sound. The strings are paired in courses as in a modern 12 string guitar, but they only have four or five courses of strings rather than six. They were more often used as rhythm instruments in ensembles than as solo instruments, and can often be seen in that role in early music performances. (Gaspar Sanz' Instrucción de Música sobre la Guitarra Española of 1674 constitutes the majority of the surviving solo corpus for the era.) Renaissance and Baroque guitars are easily distinguished because the Renaissance guitar is very plain and the Baroque guitar is very ornate, with inlays all over the neck and body, and a paper-cutout inverted "wedding cake" inside the hole.

• Classical guitars: These are typically strung with nylon strings, played in a seated position and are used to play a diversity of musical styles including classical music. The classical guitar is designed to allow for the execution of solo polyphonic arrangements of music in much the same manner as the pianoforte can. This is the major point of difference in design intent between the classical instrument and other designs of guitar. Flamenco guitars are very similar in construction, have a sharper sound, and are used in flamenco. In Mexico, the popular mariachi band includes a range of guitars, from the tiny requinto to the guitarron, a guitar larger than a cello, which is tuned in the bass register. In Colombia, the traditional quartet includes a range of instruments too, from the small bandola (sometimes known as the Deleuze-Guattari, for use when travelling or in confined rooms or spaces), to the slightly larger tiple, to the full sized classical guitar. Modern dimensions of the classical instrument were established by Antonio Torres Jurado (1817-1892). Classical guitars are sometimes referred to as classic guitars, which is a more proper translation from the Spanish.

• Portuguese guitar: Is a 12 string guitar used in Portugal for the traditional Fado song. Its true origins are somewhat uncertain but there is a general agreement that it goes back to the medieval period. It is often mistakenly thought of to be based on the so-called "English guitar" - a common error as there is no such thing. For some time the best instruments of this and other types were made in England, hence the confusion. "English guitar" refers to a quality standard, not really an instrument type. This particular instrument is most likely a merge of medieval "cistre" or "citar" and the Arabic lute.

• Flat-top (steel-string) guitars: Similar to the classical guitar, however the body size is usually significantly larger than a classical guitar and it has a narrower, reinforced neck and stronger structural design, to sustain the extra tension of steel strings which produce a brighter tone, and according to some players, a louder sound. The acoustic guitar is a staple in folk, Old-time music and blues.

• Archtop guitars are steel string instruments which feature a violin-inspired f-hole design in which the top (and often the back) of the instrument are carved in a curved rather than a flat shape. Lloyd Loar of the Gibson Guitar Corporation invented this variation of guitar after designing a style of mandolin of the same type. The typical Archtop is a hollow body guitar whose form is much like that of a mandolin or violin family instrument and may be acoustic or electric. Some solid body electric guitars are also considered archtop guitars although usually 'Archtop guitar' refers to the hollow body form. Archtop guitars were immediately adopted upon their release by both jazz and country musicians and have remained particularly popular in jazz music, usually using thicker strings (higher gauged round wound and flat wound) than acoustic guitars. Archtops are often louder than a typical dreadnought acoustic guitar. The electric hollow body archtop guitar has a distinct sound among electric guitars and is consequently appropriate for many styles of rock and roll. Many electric archtop guitars intended for use in rock and roll even have a Tremolo Arm.

• Resonator, resophonic or Dobro guitars: Similar to the flat top guitar in appearance, but with sound produced by a metal resonator mounted in the middle of the top rather than an open sound hole, so that the physical principle of the guitar is actually more similar to the banjo. The purpose of the resonator is to amplify the sound of the guitar; this purpose has been largely superseded by electrical amplification, but the resonator is still played by those desiring its distinctive sound.

  Resonator guitars may have either one resonator cone or three resonator cones. Three cone resonators have two cones on the left above one another and one cone immediately to the right. The method of transmitting sound resonance to the cone is either a BISCUIT bridge, made of a small piece of hardwood, or a SPIDER bridge, made of metal and larger in size. Three cone resonators always use a specialised metal spider bridge.

  The type of resonator guitar with a neck with a square cross-section -- called "square neck" -- is usually played face up, on the lap of the seated player, and often with a metal or glass slide. The round neck resonator guitars are normally played in the same fashion as other guitars, although slides are also often used, especially in blues.

• 12 string guitars usually have steel strings and are widely used in folk music, blues and rock and roll. Rather than having only six strings, the 12-string guitar has pairs, like a mandolin. Each pair of strings is tuned either in unison (the two highest) or an octave apart (the others). They are made both in acoustic and electric forms.

• Russian guitars are seven string acoustic guitars which were the norm for Russian guitarists throughout the 19th and well into the 20th centuries. The guitar is traditionally tuned to an open G major tuning.

• Acoustic bass guitars are an acoustic version of the electric bass guitar, it has steel strings and the same tuning.

• Tenor guitars There's very sketchy background information about tenor guitars on the World Wide Web. A number of classical guitarists call the Niibori prime guitar a "Tenor Guitar" on the grounds that it sits in pitch between the alto and the bass. Elsewhere, the name is taken for a 4-string guitar, with a scale length of 23" (585mm) - about the same as a Terz Guitar. But the guitar is tuned in fifths - C G D A - like the tenor banjo or the cello. Indeed it is generally accepted that the tenor guitar was created to allow a tenor banjo player to follow the fashion as it evolved from from Dixieland Jazz towards the more progressive Jazz that featured guitar. It allows a tenor banjo player to provide a guitar-based rhythm section with nothing to learn. A small minority of players close tuned the instrument to D G B E to produce a deep instrument that could be played with the 4-note chord shapes found on the top 4 strings of the guitar or ukulele. In fact, though, the deep pitch warrants the wide-spaced chords that the banjo tuning permits, and the close tuned tenor does not have the same full, clear sound.

• Harp guitars. Harp Guitars are difficult to classify as there are many variations within this type of guitar. They are typically rare and uncommon in the popular music scene. Most consist of a regular guitar, plus additional 'harp' strings strung above the six normal strings. The instrument is usually acoustic and the harp strings are usually tuned to lower notes than the guitar strings, for an added bass range. Normally there is neither fingerboard nor frets behind the harp strings. Some harp guitars also feature much higher pitch strings strung below the traditional guitar strings. The number of harp strings varies greatly, depending on the type of guitar and also the player's personal preference (as they have often been made to the player's specification). The Pikasso guitar; 4 necks, 2 sound holes, 42 strings] and also the Oracle Harp Sympitar; 24 strings (with 12 sympathetic strings protruding through the neck) are modern examples.

• Extended-range guitars. For well over a century guitars featuring seven, eight, nine, ten or more strings have been used by a minority of guitarists as a means of increasing the range of pitch available to the player. Usually this entails the addition of extra bass strings.

• Guitar battente. The battente is smaller than a classical guitar, usually played with four or five metal strings. It is mainly used in Calabria (a region in southern Italy) to accompany the voice.

Electric guitars

Electric guitars can have solid, semi-hollow, or hollow bodies, and produce little sound without amplification. Electromagnetic pickups (single and double coil) convert the vibration of the steel strings into electrical signals which are fed to an amplifier through a cable or radio transmitter. The sound is frequently modified by other electronic devices or the natural distortion of valves (vacuum tubes) in the amplifier. The electric guitar is used extensively in jazz, blues and rock and roll, and was commercialized by Gibson together with Les Paul and independently by Leo Fender. The lower fretboard action (the height of the strings from the fingerboard) and its electrical amplification lend the electric guitar to some techniques which are less frequently used on acoustic guitars. These techniques include tapping, extensive use of legato through pull-offs and hammer-ons (also known as slurs in the traditional Classical genre), pinch harmonics, volume swells and use of a Tremolo arm or effects pedals. Seven-string solid body electric guitars were developed in the 1990s (earlier in jazz) to achieve a much darker sound through extending the lower end of the guitar's range. They are used today by players such as James "Munky" Shaffer, Dave Weiner, John Petrucci, Jeff Loomis, Steve Smyth, and Steve Vai. Meshuggah, Dino Cazares, Rusty Cooley & Charlie Hunter go a step further, using an 8 string guitar with two extra low strings. Although the most commonly found 7 string is the variety in which there is one low B string, Roger McGuinn (Of Byrds/Rickenbacker Fame) has popularized a variety in which an octave G string is paired with the regular G string as on a 12 string guitar, allowing him to incorporate chiming 12 string elements in standard 6 string playing. Ibanez makes many varieties of electric 7 strings.

The electric bass guitar is similar in tuning to the traditional double bass viol. Hybrids of acoustic and electric guitars are also common. There are also more exotic varieties, such as double-necked guitars, all manner of alternate string arrangements, fretless fingerboards (used almost exclusively on bass guitars, meant to emulate the sound of a stand-up bass), 5.1 surround guitar, and such.

Some electric guitar and electric bass guitar models feature Piezoelectric pickups, which function as small microphones to provide a sound closer to that of an acoustic guitar with the flip of a switch or knob, rather than switching guitars.

Parts of the guitar

1. Headstock
2. Nut
3. Machine heads (or pegheads, tuning keys,
   tuning machines, tuners)
4. Frets
5. Truss rod
6. Inlays
7. Neck
8. Heel (acoustic or Spanish) - Neckjoint (electric)
9. Body
10. Pickups
11. Electronics
12. Bridge
13. Pickguard
14. Back
15. Soundboard (top)
16. Body sides (ribs)
17. Sound hole, with Rosette inlay
18. Strings
19. Saddle
20. Fretboard

Headstock

The headstock is located at the end of the guitar neck furthest from the body. It is fitted with machine heads that adjust the tension of the strings, which in turn affects the pitch. Traditional tuner layout is "3+3" in which each side of the headstock has three tuners (such as on Gibson Les Pauls). In this layout, the headstocks are commonly symmetrical. Many guitars feature other layouts as well, including six-in-line (featured on Fender Stratocasters) tuners or even "4+2" (Ernie Ball Music Man). However, some guitars (such as Steinbergers) do not have headstocks at all, in which case the tuning machines are located elsewhere, either on the body or the bridge.

Nut

The nut is a small strip of bone, plastic, brass, corian, graphite, stainless steel, or other medium-hard material, at the joint where the headstock meets the fretboard. Its grooves guide the strings onto the fretboard, giving consistent lateral string placement. It is one of the endpoints of the strings' vibrating length. It must be accurately cut, or it can contribute to tuning problems due to string slippage, and/or string buzz.

Fretboard

Also called the fingerboard, the fretboard is a piece of wood embedded with metal frets that comprises the top of the neck. It is flat on classical guitars and slightly curved crosswise on acoustic and electric guitars. The curvature of the fretboard is measured by the fretboard radius, which is the radius of a hypothetical circle of which the fretboard's surface constitutes a segment. The smaller the fretboard radius, the more noticeably curved the fretboard is. Most modern guitars feature a 12" neck radius, while older guitars from the '60's and '70's usually feature a 6" - 8" neck radius. Pinching a string against the fretboard effectively shortens the vibrating length of the string, producing a higher pitch. Fretboards are most commonly made of rosewood, ebony, maple, and sometimes manufactured or composite materials such as HPL or resin.

Frets

Frets are metal strips (usually nickel alloy or stainless steel) embedded along the fretboard which are placed in points along the length of string that divide it mathematically. When strings are pressed down behind them, frets shorten the strings' vibrating lengths to produce different pitches- each one is spaced a half-step apart on the 12 tone scale. For more on fret spacing, see the Strings and Tuning section below. Frets are usually the first permanent part to wear out on a heavily played electric guitar. They can be re-shaped to a certain extent and can be replaced as needed. Frets also indicate fractions of the length of a string (the string midpoint is at the 12th fret; one-third the length of the string reaches from the nut to the 7th fret, the 7th fret to the 19th, and the 19th to the saddle; one-quarter reaches from nut to fifth to twelfth to twenty-fourth to saddle). This feature is important in playing harmonics. Frets are available in several different gauges, depending on the type of guitar and the player's style.

Guitars have frets on the fingerboard to fix the positions of notes and scales, which gives them equal temperament. Consequently, the ratio of the spacing of two consecutive frets is the twelfth root of two ${\displaystyle {\sqrt{2}}}$, whose numeric value is about 1.059463. The twelfth fret divides the scale length in two exact halves and the 24th fret (if present) divides the scale length in half yet again. Every twelve frets represents one octave. In practice, luthiers determine fret positions using the constant 17.817152, which is derived from the twelfth root of two. The scale length divided by this value yields the distance from the nut to the first fret. That distance is subtracted from the scale length and the result is divided in two sections by the constant to yield the distance from the first fret to the second fret. Positions for the remainder of the frets are calculated in like manner.

There are several styles of fret, which allow different sounds and techniques to be exploited by the player. Among these are "jumbo" frets, which have much thicker wires, allowing for a lighter touch and a slight vibrato technique simply from pushing the string down harder and softer, "scalloped" fretboards, where the wood of the fretboard itself is "scooped out", becoming deeper away from the headstock, which allows a dramatic vibrato effect and other unusual techniques, and fine frets, much flatter, which allow a very low string-action for extremely fast playing, but require other conditions (such as curvature of the neck) to be kept in perfect order to prevent buzz.

Truss rod

The truss rod is a metal rod that runs along the inside of the neck. Its tension is adjusted by a hex nut or an allen-key bolt usually located either at the headstock (sometimes under a cover) or just inside the body of the guitar, underneath the fretboard (accessible through the sound hole). Some truss rods can only be accessed by removing the neck, forcing the luthier to replace it after every adjustment to check its accuracy. The truss rod counteracts the immense amount of tension the strings place on the neck, bringing the neck back to a straighter position. The truss rod can be adjusted to compensate for changes in the neck wood due to changes in humidity or to compensate for changes in the tension of strings. Tightening the rod will curve the neck back and loosening it will return it forward. Adjusting the truss rod affects the intonation of a guitar as well as affecting the action (the height of the strings from the fingerboard). Some truss rod systems, called "double action" truss systems, will tighten both ways, allowing the neck to be pushed both forward and backward (most truss rods can only be loosened so much, beyond which the bolt will just come loose and the neck will no longer be pulled backward). Most classical guitars do not have truss rods, as the nylon strings do not put enough tension on the neck for one to be needed.

Inlays

Inlays are visual elements set into the exterior frame of a guitar. The typical locations for inlay are on the fretboard, headstock, and around the soundhole (called a rosette on acoustic guitars). Inlays range from simple plastic dots on the fretboard to fantastic works of art covering the entire exterior surface of a guitar (front and back). Some guitar players (notably Steve Vai and Sam Rivers, bassist of rock group Limp Bizkit) put LEDs in the fretboard as inlays to produce a unique lighting effect onstage.

Fretboard inlays are most commonly shaped like dots, diamond shapes, parallelograms, or large blocks in between the frets. Dots are usually inlaid into the upper edge of the fretboard in the same positions, small enough to be visible only to the player. Some manufacturers go beyond these simple shapes and use more creative designs such as lightning bolts or letters and numbers. The simpler inlays are often done in plastic on guitars of recent vintage, but many older, and newer, high-end instruments have inlays made of mother of pearl, abalone, ivory, coloured wood or any number of exotic materials. On some low-end guitars, they are just painted. Most high-end classical guitars have no inlays at all since a well trained player is expected to know his or her way around the instrument, however players will sometimes make indicators with a marker pen, correction fluid, or a small piece of tape.

The most popular fretboard inlay scheme involves single inlays on the 3rd, 5th, 7th, 9th, 15th, 17th, 19th, and 21st frets, and double inlays on the 12th, sometimes 7th, and (if present) 24th fret. Advantages of such scheme include its symmetry about the 12th fret and symmetry of every half (0-12 and 12-24) about the 7th and 19th frets. However, playing these frets, for example, on E string would yield notes E, G, A, B, C# that barely makes a complete musical mode by themselves.

A less popular fretboard inlay scheme involves inlays on 3rd, 5th, 7th, 10th, 12th, 15th, 17th, 19th, 22nd and 24th frets. Playing these frets, for example, on E string yields notes E, G, A, B, D that fit perfectly into E minor pentatonic. Such a scheme is very close to piano keys colouring (which involves black colouring for sharps that pentatonic consists of) and of some use on classic guitars.

Beyond the fretboard inlay, the headstock and soundhole are also commonly inlaid. The manufacturer's logo is commonly inlaid into the headstock. Sometimes a small design such as a bird or other character or an abstract shape also accompanies the logo. The soundhole designs found on acoustic guitars vary from simple concentric circles to delicate fretwork (referred to as a Rosette). Many high-end guitars have more elaborate decorative inlay schemes. Often the edges of the guitar around the neck and body and down the middle of the back are inlaid. The fretboard commonly has a large inlay running across several frets or the entire length of the fretboard, such as a long vine creeping across the fretboard. Most acoustic guitars have an inlay that borders the sides of the fretboard, and some electrics (namely Fender Stratocasters) have what looks like a wood inlay running on the back of the neck, from about the body to the middle of the neck, commonly referred to as a skunk stripe. In fact this is a filler strip, used to fill the cavity through which the trussrod was installed in the neck.

Some very limited edition high-end or custom-made guitars have artistic inlay designs that span the entire front (or even the back) of the guitar. These designs use a variety of different materials and are created using techniques borrowed from furniture making. While these designs are often just very elaborate decorations, they are sometimes works of art that even depict a particular theme or a scene. Although these guitars are often constructed from the most exclusive materials, they are generally considered to be collector's items and not intended to be played. Large guitar manufacturers often issue these guitars to celebrate a significant historical milestone.

Neck

A guitar's frets, fretboard, tuners, headstock, and truss rod, all attached to a long wooden extension, collectively constitute its neck. The wood used to make the fretboard will usually differ from the wood in the rest of the neck. The bending stress on the neck is considerable, particularly when heavier gauge strings are used (see Strings and tuning), and the ability of the neck to resist bending (see Truss rod) is important to the guitar's ability to hold a constant pitch during tuning or when strings are fretted. The rigidity of the neck with respect to the body of the guitar is one determinant of a good instrument versus a poor one. The shape of the neck can also vary, from a gentle "C" curve to a more pronounced "V" curve. There are many different types of neck profiles available, giving the guitarist many options. Some aspects that to consider in a guitar neck may be the overall width of the fingerboard, scale (distance between the frets), the neck wood the type of neck construction (For example, the neck may be glued in or bolted on), and the shape (profile) of the back of the neck.

Neck joint or 'Heel'

This is the point at which the neck is either bolted or glued to the body of the guitar. Almost all acoustic guitars, with the primary exception of Taylors, have glued (otherwise known as set) necks, while electric guitars are constructed using both types.

Commonly used set neck joints include mortise and tenon joints (such as those used by CF Martin & Co. guitars), dovetail joints (also used by CF Martin on the D28 and similar models) and Spanish heel neck joints which are named after the shoe they resemble and commonly found in classical guitars. All three types offer stability and sustain. Bolt-on necks, though they are historically associated with cheaper instruments, do offer greater flexibility in the guitar's set-up, and allow easier access for neck joint maintenance and repairs.

Another type of neck, only available for solid body electric guitars, is the Neck-through-body construction. These are designed so that everything from the machine heads down to the bridge are located on the same piece of wood. The sides (also known as wings) of the guitar are then glued to this central piece. Some luthiers prefer this method of construction as it is said to allow better sustain of each note. Some instruments may not have a neck joint at all, having the neck and sides built as one piece and the body built around it.

Strings

Guitar strings are strung almost parallel to the neck, whose surface is covered by the fingerboard (fretboard). By depressing a string against the fingerboard, the effective length of the string can be changed, which in turn changes the frequency at which the string will vibrate when plucked. Guitarists typically use one hand to pluck the strings and the other to depress the strings against the fretboard.

Traditionally the dominant hand is assigned the task of plucking or strumming the strings. For the majority of people this entails using the right hand. This is because musical expression (dynamics, tonal expression and colour etc) is largely determined by the plucking hand, whilst the fretting hand is assigned the lesser mechanical task of depressing and gripping the strings. This is similar to the convention of the violin family of instruments where the right hand controls the bow. A minority however believe that left-handed people should learn to play "conventional" guitars strung in the manner used by right-handed people, simply to standardise the instrument.

The strings may be plucked using either fingers or a plectrum (Guitar pick).The sound of the guitar is achieved either mechanically or electronically, forming two main categories of guitar: acoustic (mechanical amplification) and electric (electronic amplification).

• In acoustic guitars, string vibration is transmitted through the bridge and saddle to the sound board. The sound board, typically made of a light springy wood such as spruce, vibrates the air, producing sound which is further shaped by the guitar body's resonant cavity.

• In electric guitars, transducers known as pickups convert string vibration to an electronic signal, which in turn is amplified and fed to speakers, which vibrate the air to produce the sound we hear.

Body (acoustic guitar)

The body of the instrument is a major determinant of the overall sound variety for acoustic guitars. The guitar top, or soundboard, is a finely crafted and engineered element often made of tonewood like spruce, red cedar or mahogany. This thin (often 2 or 3 mm thick) piece of wood, strengthened by different types of internal bracing, is considered to be the most prominent factor in determining the sound quality of a guitar. The majority of the sound is caused by vibration of the guitar top as the energy of the vibrating strings is transferred to it. It is thought that the details of the way in which the guitar top vibrates (characterised by many different modes of vibration at different frequencies) is a key influence on the timbre of the radiated sound. Different patterns of wood bracing have been used through the years by luthiers (Torres, Hauser, Ramirez, Fleta, and C.F. Martin being among the most influential designers of their times); to not only strengthen the top against collapsing under the tremendous stress exerted by the tensioned strings, but also to affect the resonance characteristics of the top. The back and sides are made out of a variety of tonewoods such as mahogany, Indian rosewood and highly regarded Brazilian rosewood (Dalbergia nigra). Each one is chosen for their aesthetic effect and structural strength, and can also play a significant role in determining the instrument's timbre. These are also strengthened with internal bracing, and decorated with inlays and purfling.

The body of an acoustic guitar has a sound hole and acts as a resonating chamber. The sound hole is normally a round hole in the top of the guitar (under the strings), though some may have different placement, shapes or multiple holes. Air inside the body vibrates as the guitar top is vibrated by the strings, and the response of the air cavity at different frequencies is characterised, like the rest of the guitar body, by a number of resonance modes at which it responds more strongly. Some sound is radiated by the movement of the air in and out of the sound hole, although the guitar top is the main radiator of sound.

Instruments with larger areas for the guitar top may have greater sound-radiating abilities, making higher volume of sound possible (although tone quality will also be affected by guitar top size and design). The popularity of the Dreadnought body size amongst acoustic performers may relate to the greater sound volume produced.

However, whilst the '00' pattern is a post-modern evolution in the wake of affordable wire-drawing and truss-turning technologies, musicians wishing to explore the nature of performance in the taverna or salon environments which overlapped early recording technologies may wish to consider the role of the 3/4-size as well as the Ordinary, or '0', guitar, particularly where a duo or ensemble is called for and space is at a premium.

Body (electric guitar)

Most electric guitar bodies are made of wood with a plastic pick guard. Boards wide enough to use as a solid body are very expensive, so the wood is rarely one solid piece. Most bodies are made of two pieces of wood with a seam running down the centre line of the body. The most common woods used for electric guitar body construction include maple, basswood, ash, poplar, alder, and mahogany. Many bodies will consist of good sounding but inexpensive woods, like ash, with a "top", or thin layer of another, more attractive wood (such as maple with a natural "flame" pattern) glued to the top of the basic wood. Guitars constructed like this are often called "flame tops". The body is usually carved or routed to accept the other elements, such as the bridge, pickup, neck, and other electronic components. Most electrics have a polyester or nitrocellulose lacquer finish.

Pickups

Pickups are electronic devices attached to a guitar that detect (or "pick up") string vibrations and allow the sound of the string to be amplified. Pickups are usually placed right underneath the guitar strings. The most common type of pickups contain magnets that are tightly wrapped in copper wire. Pickups work on a similar principle to a electrical generator in that the vibration of the strings causes a small voltage to be created in the coils surrounding the magnets. This signal is later amplified by an amplifier.

Traditional electric pickups are either single-coil or double-coil. Double-coil pickups are also known as humbuckers for their noise-cancelling ability. The type and model of pickups used can greatly affect the tone of the guitar. Typically, humbuckers, which are two magnets attached to each other and each wrapped in copper wire, are used by guitarists seeking a heavier sound. Single coil pickups, one magnet wrapped in copper wire, are used by guitarists seeking a brighter, twangier sound with greater dynamic range. However, a disadvantage of single coil pickups is mains-frequency (60 or 50 hertz) hum. Some guitars need a battery to power their pickups and/or pre-amp; these guitars are referred to as having "active electronics", as opposed to the typical "passive" circuits.

The Fender Stratocaster type guitars generally utilize 3 single coil pickups, while the Gibson Les Paul types use humbucker pickups.

A further type of pickup is the piezo pickup. These employ piezoelectricity to generate the musical signal and are popular in hybrid electro-acoustic guitars. Usually, a crystal is located in the saddle under each string. When the string vibrates, the shape of the crystal is distorted, and this change in shape produces a tiny voltage that can be amplified and manipulated.

Some guitars have what is called a hexaphonic pickup. These pickups are also piezo pickups. "Hex" is a prefix meaning six. In a hexaphonic pickup there is a separate piezo pickup wired for each of six strings. This arrangement allows the signal to be easily modified by on-board modelling electronics, as in the Line 6 Variax brand of electric guitars, the guitars allow for a variety of different sounds to be obtained by digitally modelling the vibration. This results in a guitar which is able to mimic many vintage models, as well as output alternate tunings (e.g. Drop D) without the need to adjust the strings. The benefits of using a piezo pickup include the ability to bend strings and use palm/neck muting. Another use for hexaphonic pickups is to send the signal (that is the six separate signals) to a MIDI interpretation device, which determines the note pitch, duration, attack and decay characteristics, and so forth. The MIDI (Musical Instrument Digital Interface) interpreter then sends the note information to a sound bank device. The resulting sounds can closely mimic a piano, trumpet or other brass instrument, harmonica or any of numerous other instruments.

Electronics

On guitars that have them, these components and the wires that connect them allow the player to control some aspects of the sound like volume or tone. These at their simplest consist of passive components such as potentiometers and capacitors, but may also include specialised integrated circuits or other active components requiring batteries for power, for preamplification and signal processing, or even for assistance in tuning. In many cases the electronics have some sort of shielding to prevent pickup of external interference and noise.

Lining, Binding, Purfling

The top, back and ribs of an acoustic guitar body are very thin (1-2 mm), so a flexible piece of wood called lining is glued into the corners where the rib meets the top and back. This interior reinforcement provides 5 to 20 mm of solid gluing area for these corner joints. Solid linings are often used in classical guitars, while kerfed lining is most often found in steel string acoustics. Kerfed lining is also called kerfing (because it is scored, or kerfed to allow it to bend with the shape of the rib).

During final construction, a small section of the outside corners is carved or routed out and then filled with binding material on the outside corners and decorative strips of material next to the binding, which are called purfling. This binding serves to seal off the endgrain of the top and back. Purfling can also appear on the back of an acoustic guitar, marking the edge joints of the two or three sections of the back.

Binding and purfling materials are generally made of either wood or plastic.

Bridge

The main purpose of the bridge on an acoustic guitar is to transfer the vibration from the strings to the soundboard, which vibrates the air inside of the guitar, thereby amplifying the sound produced by the strings.

On both electric and acoustic guitars, the bridge holds the strings in place on the body. There are many varied bridge designs. There may be some mechanism for raising or lowering the bridge to adjust the distance between the strings and the fretboard (action), and/or fine-tuning the intonation of the instrument. Some are spring-loaded and feature a "whammy bar", a removable arm which allows the player to modulate the pitch moving the bridge up and down. The whammy bar is sometimes also referred to as a "tremolo bar" (see Tremolo for further discussion of this term - the effect of rapidly changing pitch produced by a whammy bar is more correctly called "vibrato"). Some bridges also allow for alternate tunings at the touch of a button.

On almost all modern electric guitars, the bridge is adjustable for each string so that intonation stays correct up and down the neck. If the open string is in tune but sharp or flat when frets are pressed, the bridge can be adjusted with a screwdriver or hex key to remedy the problem. In general, flat notes are corrected by moving the bridge forward and sharp notes by moving it backwards. On an instrument correctly adjusted for intonation, the actual length of each string from the nut to the bridge saddle will be slightly but measurably longer than the scale length of the instrument. This additional length is called compensation, which flattens all notes a bit to compensate for the sharping of all fretted notes caused by stretching the string during fretting.

Pickguard

Also known as a scratchplate. This is usually a piece of plastic or other laminated material that protects the finish of the top of the guitar. In some electric guitars, the pickups and most of the electronics are mounted on the pickguard. On acoustic guitars and many electric guitars, the pickguard is mounted directly to the guitar top, while on guitars with carved tops (for example, the Gibson Les Paul), the pickguard is elevated. The Pickguard is more often than not used in styles such as flamenco, which tends to use the guitar as a percussion instrument at times, rather than for instance, a classical guitar.

Tuning

The guitar is a transposing instrument. Its pitch sounds one octave lower than it is notated.

A variety of different tunings are used. The most common by far, known as "Standard Tuning" (EADGBE), is as follows:

• sixth (lowest tone) string: E (a minor thirteenth below middle C—82.4 Hz)
• fifth string: A (a minor tenth below middle C—110 Hz)
• fourth string: d (a minor seventh below middle C—146.8 Hz)
• third string: g (a perfect fourth below middle C—196.0 Hz)
• second string: b (a minor second below middle C—246.92 Hz)
• first (highest tone) string: e' (a major third above middle C—329.6 Hz)

A guitar using this tuning can tune to itself by the fact, with a single exception, that the 5th fret on one string is the same note as the next open string; that is, a 5th-fret note on the sixth string is the same note as the open fifth string. The exception to this rule is the interval between the second and third strings, in which the 4th-fret note on the third string is equivalent to the open second string.

Standard tuning has evolved to provide a good compromise between simple fingering for many chords and the ability to play common scales with minimal left hand movement. There are also a variety of commonly used alternate tunings - most of which are chord voicings that can be played on open strings or made by moving the capo.

Many guitarists use a long established (centuries old) tuning variation where the lowest string is 'dropped' two semi-tones down. Known as Drop-D (or dropped D) tuning it is, from low to high, DAdgbe'. This allows for open string tonic and dominant basses in the keys of D and D minor. It also enables simple fifths (powerchords) to be easily played without the need for a high technical skill level. Many contemporary rock bands downtune the entire tuning by several semi-tones, making, for example, Drop-C or Drop-B tunings, However this terminology is inconsistent with that of "drop-D" as "drop-D" refers to dropping a single string to the named pitch. Often these new tunings are also simply referred to as the "Standard" of the note in question e.g. - "D Standard" (DGCFAD). Many other open tunings, where all of the strings are tuned to a similar note or chord, are popular for slide guitar playing.

As with all stringed instruments a large number of scordatura are possible on the guitar.

Guitar terminology

Vibrato Arm

The Vibrato (pitch bend) unit found on many electric guitars has also had slang terms applied to it, such as "tremolo bar (or arm)", "sissy bar", "whammy handle", and "whammy bar". The latter two slang terms led stompbox manufacturers to use the term 'whammy' in coming up with a pitch raising effect introduced by popular guitar effects pedal brand "Digitech".

Leo Fender, who did much to create the electric guitar, also created much confusion over the meaning of the terms "tremolo" and "vibrato", specifically by misnaming the "tremolo" unit on many of his guitars and also the "vibrato" unit on his "Vibrolux" amps. In general, vibrato is a variation in pitch, whereas tremolo is a variation in volume, so the tremolo bar is actually a vibrato bar and the "Vibrolux" amps actually had a tremolo effect. However, following Fender's example, electric guitarists traditionally reverse these meanings when speaking of hardware devices and the effects they produce. See vibrato unit for a more detailed discussion, and tremolo arm for more of the history.

A distinctly different form of mechanical vibrato found on some guitars is the Bigsby vibrato tailpiece, commonly called Bigsby. This vibrato wraps the strings around a horizontal bar, which is then rotated with a handle by the musician.

Another type of pitch bender is the B-Bender, a spring and lever device mounted in an internal cavity of a solid body electric, guitar that allows the guitarist to bend just the B string of the guitar using a lever connected to the strap handle of the guitar. The resulting pitch bend is evocative of the sound of the pedal steel guitar.

Capotasto

A capotasto (or capo) is used to change the pitch of open strings. Capos are clipped onto the fret board with the aid of spring tension, or in some models, elastic tension. To raise the guitar's pitch by one semitone, the player would clip the capo onto the fret board just below the first fret. Their use allows a player to play in different keys without having to change the chord formations they use. Because of the ease with which they allow guitar players to change keys, they are sometimes referred to as "cheaters". Classical performers are known to use them to enable modern instruments to match the pitch of historical instruments such as the renaissance lute.

Slides

A slide, (neck of a bottle, knife blade or round metal bar) used in blues and rock to create a glissando or 'hawaiian' effect. The necks of bottles were often used in blues and country music. Modern slides are constructed of glass, plastic, chrome, brass or steel, depending on the weight and tone desired. Some muscians today choose the play slide with a shot glass. An instrument that is played exclusively in this manner, (using a metal bar) is called a steel guitar or pedal steel. Slide playing to this day is very popular in blues music and country music.

Some legends that have become famous for playing slide are Derek Trucks, Warren Haynes, Duane Allman, Muddy Waters, and Adam Carswell.

Plectrum

A "guitar pick" or "plectrum" is a small piece of hard material which is generally held between the thumb and first finger of the picking hand and is used to "pick" the strings. Though most classical players pick solely with their fingers, the "pick" is the most common means of playing used today. Though today they are mainly plastic, variations do exist, such as bone, wood, steel or tortoise shell. Tortoise shell was the most commonly used material in the early days of pick making, but as tortoises became more and more endangered, the practice of using their shells for picks or anything else was banned. Tortoise shell picks are often coveted for a supposedly superior tone and ease of use.

Picks come in many shapes and sizes. Picks vary from the small jazz pick to the large bass pick. The thickness of the pick often determines its use. A thinner pick (between .2 and .5 mm) is usually used for strumming or rhythm playing, whereas thicker picks (between .7 and 1.5+ mm) are usually used for single-note lines or lead playing. The distinctive guitar sound of Billy Gibbons is attributed to using a quarter or peso as a pick. Similarily, Brian May is known to use a sixpence coin as a pick.

Notes

1. The Classical Mandolin by Paul Sparks (1995)
2. Early Romantic Guitar
3. The Guitar and Its Music: From the Renaissance to the Classical Era by James Tyler (2002)
4. Evans, Tom and MaryAnne (1977). Guitars: Music, history, Construction and Players from the Renaissance to Rock. p. 42. ISBN 0-448-22240-X.
5. Mottola, R.M. "Lutherie Info – Calculating Fret Positions".

References

Flamenco! The Guitar and the Music - An Indiana University research paper on Flamenco, the indigenous music of the Gypsies of southern Spain, written by Jeff Foster, 1987.

See also

• List of guitar manufacturers
• 3rd Bridge
• Electric guitar
• Guitar harmonics
• Guitar effects
• Guitar amplifier
• Tablature
• Tonewood
• Guitar in popular culture
• Fretless guitar

External links

• Stalking the Oldest Six-String Guitar
• Guitar physics
• Wiki Guitar
• Audio Tabs Guitar tabs.

Template:Link FA

• Articles lacking sources from July 2006
• Guitars
• String instruments
• Folk instruments