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Guitar
History
Instruments similar to what we know as 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. 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, possibly
from earlier Greek word kithara. Prospective
sources for various names of musical instruments
that guitar could be derived from all 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 may also be 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 guitar
was introduced into Spanish when guitars were
brought into Iberia by the Moors after the 10th
century. (See related article).
The
Spanish vihuela appears to be an intermediate
form between the ancestral guitar and the modern
guitar, with lute-style tuning and a small,
but guitar-like body. It is not clear whether
this represents a transitional form or simply
a design that combined features from the two
families of instruments. (See the article on
the lute for further history.) The Ancient Iranian
lute, called tar in farsi also is found in the
word guitar. The tar is thousands of years old,
and could be found in 2, 3, 5, 6 string variations.
The
electric guitar was invented by Adolph Rickenbacher,
with the help of George Beauchamp and Paul Berth,
in 1931. Rickenbacher was the inventor of the
horseshoe-magnet pickup. However, it was Danelectro
that first produced electric guitars for the
wider public. Danelectro also pioneered tube
amp technology.
Parts
of the guitar
Guitar consists of several parts. Refer to appropriate
article for description of a part:
1.
Headstock
2. Nut
3. Machine heads
4. Frets
5. Truss rod
6. Inlays
7. Neck and fretboard
8. Neck joint
9. Body
10. Pickups
11. Electronics
12. Bridge
13. Pickguard
Headstock
The headstock is located at the end of
the guitar neck. It is fitted with the
machine head for pitch adjusting. Traditional
layout of tuners is "3+3" which
means 3 top tuners and 3 bottom ones.
Some electric guitars feature 6 in-line
tuners or even 4+2.
Nut
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The
nut is a small strip of ivory, bone, plastic,
brass, graphite, or other medium-hard material
that braces the strings at the joint where the
headstock meets the fretboard. It is grooved
to hold the strings in place, and it is one
of the endpoints of the strings' tension. The
material used also affects the sound of the
guitar.
Fretboard
Also called the fingerboard, the fretboard is
a long plank 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.
Pinching a string against the fretboard effectively
shortens the vibrating length of the string,
producing a higher tone (a string, unfingered,
will vibrate from the saddle to the nut; once
fingered, it will vibrate only along the distance
between the saddle and the fret directly before
the finger). Fretboards are most commonly made
of rosewood, ebony, maple, and sometimes graphite.
Frets
Frets are metal strips (usually nickel alloy)
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 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
widths of two consecutive frets is the twelfth
root of two , whose numeric value is about 1.059463.
The twelfth fret divides the string in two exact
halves and the 24th fret (if present) divides
the string in half yet again. Every twelve frets
represents one octave.
Truss
rod
The truss rod is an adjustable metal rod that
runs along the inside of the neck, adjusted
by a hex nut or an allen-key bolt usually located
either at the headstock (under a cover) or just
inside the body of the guitar, underneath the
fretboard (accessible through the sound hole).
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). 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
wood on 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 people put Lights inside these
to create an awesome stage affect when the lights
go out.
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. Many classical guitars have
no inlays at all; the player himself sometimes
will make them with a marker pen or correction
fluid.
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. Pros 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 make 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 coloring
(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. 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 a black 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.
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 (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. Conversely,
the ability to change the pitch of the note
slightly by deliberately bending the neck forcibly
with the fretting arm is a technique occasionally
used, particularly in the blues genre and those
derived from it, such as rock and roll. The
shape of the neck can also vary, from a gentle
"C" curve to a more pronounced "V"
curve.
Neck
joint
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 (or set) necks, while
electric guitars are constructed using both
types. Set necks usually feature dovetail joints,
which offer stability and sustain. Other commonly
used neck joints include mortise-and-tenon joints
(such as those used by CF Martin & Co. guitars),
and Spanish Heel style neck joints (commonly
found in classical guitars). 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. Some
very high-end instruments may not have a neck
joint at all, having the neck and sides built
as one piece and the body built around it.
Body
(acoustic guitar)
The body of the instrument is a major determinant
of the overall sound for acoustic guitars. The
guitar top, or soundboard, is a finely crafted
and engineered element often made of 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; to not only strengthen the top against
collapsing under the tremendous stress exerted
by the tensioned strings (Torres, Hauser, Ramirez,
Fleta being among the most influential designers
of their time), but also to affect the resonation
of the top. The back and sides are made out
of a variety of woods 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, decorated with inlays
and purfling, and subjected to a lot of abuse.
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,
though some may have different shapes or multiple
holes.
Body
(electric guitar)
Most electric guitar bodies are made of wood.
This wood is rarely one solid piece, as laminating
hardwoods in the proper way can produce a body
of exceptional strength and superior tone. 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. Many
higher-end electrics have a nitro-cellulose
laquer finish on the top, which promotes resonance.
Pickups
The electric guitar is usually not very loud
when it is played without an amplifier. 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. This allows
the pickups to measure the movement of the steel
guitar string within the magnetic field above
the pickup. Some acoustic guitars also have
microphones or pickups built into them for stage
work. Pickups work on a similar principle to
a generator in that the vibration of the strings
causes a small current to be created in the
coils surrounding the magnets. This signal is
later amplified by an amplifier. However, a
new type of pickup, called a Q-Tuner pickup,
has been developed that measures the magnetic
flux density of multiple magnets located in
the pickup. These pickups produce a better tone
and pick up harmonic frequencies better than
standard pickups, but they cost more and are
more difficult to wire.
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 have large effects
on the tone of the guitar. Typically, humbuckers
are used by guitarists seeking a heavier sound.
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.
Guitar
Synthesisers may have specialist 'cluster' pickups,
effectively giving each string its own pickup.
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 magnetic shielding to prevent pickup
of external interference and noise.
Purfling
and Binding
This is the decorative edge found around the
body of an acoustic guitar. Its purpose is not
merely decorative, however. Because of the construction
methods, the edges of the body are typically
the weakest point of the acoustic guitar. There
is not much wood there, as the sides have to
be thin to allow for bending, and the top and
back have to be thin to allow the string vibrations
to resonate. Trying to connect two thin pieces
of wood at a 90 degree angle is an engineering
challenge. So to help, the purfling is used.
The corners are overbuilt, using a triangular
piece of scored wood (called a kerfed lining)
on the interior of the instrument to allow it
to follow the contours, and is glued in place.
During final construction, a small section of
the outside corners is carved or routed out
and then filled in with the purfling or binding
material.
In
mass produced guitars, the binding or purfling
is almost exclusively high quality plastic.
Once the purfling is glued in place, it is an
integral part of the guitar, and contributes
greatly to the durability of the instrument,
since plastic tends not to split as wood does
upon impact.
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. From there, the
variations are astounding. 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 springloaded
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 incorrectly referred to as
a "tremolo bar"; unlike the change
in pitch that the whammy bar produces, a tremolo
is a quick oscillation of the volume. Some bridges
allow for alternate tunings at the touch of
a button.
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 (e.g.
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.
Strings
Guitars usually have six strings, although there
are variations on this, the most common being
a twelve-string guitar; the seven string guitar;
the ukulele, which has four strings; and the
bass guitar, which usually has four strings
but also exists in five, six, eight, and twelve-string
versions. There are also more exotic models
involving multiple necks and pickups.
The
weight of a string is determined by its diameter
and is normally measured in thousandths of an
inch. The larger the diameter the heavier the
string is (with thinner strings being lighter).
Heavier strings require more tension for the
same pitch and are consequently harder to hold
on to the fretboard. Heavier strings will also
produce a louder note and for this reason steel-strung
acoustic guitars will normally be strung heavier
than electric guitars. On electric guitars,
heavier strings may also produce a thicker tone,
leading to their use by rhythm guitarists in
rock music.
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