# Guitar

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, used in a wide variety of musical styles, as acoustic and electric models, in both classical and contemporary forms. It is most recognized in popular culture as the primary instrument in blues, country, flamenco, pop, and rock musical genres. The guitar usually has six strings or in the case of a base or tenor guitar, four. Seven-, eight-, ten-, and twelve-string versions also exist. The instrument's name appears to have come from the Indo-European "guit-" (similar to the Sanskrit, "sangeet") meaning "music," and "-tar," meaning "chord" or "string."

The guitar's presence in today's popular music scene is ubiquitous, and its impact on popular culture, beginning in the 1950s, has been immense as a highly proficient means to express one's creative impulse through song. Due to the instrument's scopic range of sound, it is valued by enthusiasts as an extremely personal instrument, able to be almost an extension of the body and provide form to nearly whatever sonance one can conceptualize.

Due to the guitar's wide range and generally facile usability, it has become a staple in the world of art and entertainment, and a significant tool in the artist's pursuit to manifest beauty through sound.

## History

Figurines playing the ancestor of the Guitar. Excavated in Susa, Iran. Dated 2000-1500 B.C.E. Kept at the National Museum of Iran.

Instruments similar to the guitar have been popular for at least 5,000 years, as evident in ancient carvings and statues recovered from the ancient Iranian capital, Susa. There is evidence that a four string, guitar-like instrument called the tanbur was played by the Hittites (who occupied a region now known as Asia Minor and Syria) around 1400 B.C.E. It had characteristically soft, curved sides—one of the primary features of anything identifiable as a guitar or predecessor. The ancient Greek's probably used the Arabic tanbur as a model for their own "kithara," which was essentially a lyre with a flat back.

Some experts suggest that a modified "kithara" called a "cithara" traveled with the Romans into Spain in 400 C.E. where it cemented itself into the culture as the "guitarra."[1] The opposing theory is that the modern guitar's true ancestor is the Moors' ud, an instrument that did not enter Spain until after their invasion of the country in the eighth century. However, a more popular theory of late is that the Spanish guitar did in fact derive directly from the tanbur of the Hittites as it evolved into the Greek kithara and Roman cithara, and was probably influenced in its evolution by the Moorish ud.

By 1200 C.E., a four-string guitar had evolved into two types: The guitarra morisca (Moorish guitar) which had a rounded back, wide fingerboard and several soundholes, and the guitarra latina (Latin guitar) which resembled the modern guitar with one soundhole and a narrower neck. In the late 1400's, the vihuela was born by increasing its size and adding doubled strings. It was a large plucked instrument with a long neck that had ten or eleven frets and six courses. It was the vihuela which became the preferred instrument of the Spanish and Portuguese courts and remained so until the late 1600s, when orchestral and keyboard instruments became more prominent.

At the end of the seventeenth century the vihuela was slowly replaced by the four and five course guitars (which had seven and nine strings respectively), as this gave it more flexibility and range. It is not clear whether the brief popularity of the vihuela represented a transitional form of the guitar or was simply a design that combined features of the Moorish 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 oud.

By the end of the eighteenth century and the beginning of the nineteenth, an instrument that would unmistakably be recognized by today's individual as a guitar began to appear. These guitars were equipped with six single strings; fan struts underneath the sound board; a reinforced, raised neck for the fingerboard; and machine tuners in place of the previously used wooden pegs.

Image:Jan Vermeer van Delft 013.jpg|thumb|right|The guitar player (c. 1672), by Johannes Vermeer.]] Beginning in the early nineteenth century, in the works of Spanish luthiers Augustin Caro, Manual Gonzales, Antonio de Lorca, and Manuel Guiterrez, as well as other European makers including Rene Lacote and Johann Staufer, we find the most direct predecessors of the modern classical guitar. In 1850, the guitar went through its most significant breakthrough when Antonio Torres Jurado refined the instrument to include as many as seven struts spread out like a fan under the soundboard. He also increased the size of the body as well as the width of the neck. These modifications allowed for greater volume and bass response as well as the development of a left hand technique for richer repertoire. It was after Jurado's work that the instrument was prepared for the demands of the solo performer and the concert stage.

There have been only minor modifications since the middle 1800's, but for the most part the modern guitar resembles its 150-year-old ancestry. One notable advancement however was the advent of the electric guitar, patented by George Beauchamp in 1936. However, it was the manufacturer Danelectro that used Beauchamp's design and began to produce for the first time electric guitars for the wider public. Though the electric guitar has become widely popular in almost every contemporary genre, the acoustic guitar remains just as popular as it has always been.

The guitar became a household instrument beginning in the 1950s, when its use in rock and roll made it both fashionable and accessible to anyone keen to play. Today, it is not uncommon to see at least one guitar in most homes or to meet someone with at least intermediate skills in its use.

## Types of guitar

### 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: the steel string guitar, the folk guitar, the twelve string guitar, and the arch top guitar. A recent arrival in the acoustic guitar group is the acoustic bass guitar.

• 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 of that era.) Renaissance and Baroque guitars are easily distinguished as 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, from the small bandola (sometimes known as the Deleuze-Guattari, for use when traveling 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 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 combination of the 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.
• 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 twentieth centuries. The guitar is traditionally tuned to an open G major tuning.
• Acoustic bass guitars: also have steel strings, and match the tuning of the electric bass, which is likewise similar to the traditional double bass viol, or "big bass," a staple of string orchestras and bluegrass bands alike.
• Tenor guitars: There is a lack of background information about tenor guitars. 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" (585 mm)—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

Main article: Electric guitar
This Fender Stratocaster has features common to many electric guitars: multiple pickups, a whammy bar, volume and tone knobs.

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 the Gibson Guitar Corporation 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 viola. 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), 5.1 surround guitars, in addition to others.

## Parts of the guitar

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 in fretless guitars and basses, 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 '60s and '70s 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 $\sqrt[12]{2}$, 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.[2]

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, colored 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 coloring 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 comprise 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, and the ability of the neck to resist bending 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 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, color, and so on) 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 standardize 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. 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 resonation 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 is a resonating chamber which projects the vibrations of the body through a sound hole, allowing the acoustic guitar to be heard without amplification. 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.

### 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 modeling 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 modeling 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 specialized 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." 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, 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 for example—"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 (United States quarter]] or peso as a pick. Similarily, Brian May is known to use a sixpence coin as a pick.

## Notes

1. Maurice J. Summerfield, The Classical Guitar, Its Evolution, Players and Personalities Since 1800 (Ashley Mark, 1992).
2. R.M. Mottola, Lutherie Info – Calculating Fret Positions. Retrieved February 4, 2009.

## References

• Bacon, Tony. History of the American Guitar. Friedman, 2001. ISBN 1-586-63297-3.
• Fleming, Tom. The Complete Guitar Course: Learn to Play in 20 Easy to Follow Lessons. Pleasantville, NY: Readers Digest Association, 2006. ISBN 0-762-10662-X.
• Hunter, Dave. Acoustic Guitars: The Illustrated Encyclopedia. Thunder Bay Press, 2006. ISBN 1-592-23676-6.