Editing Cello (section)

==Construction==
[[File:Cello Parts.jpg|thumb|Main parts of the cello|upright=1.05]]
The cello is typically made from carved wood, although other materials such as [[carbon fiber]] or aluminum may be used. A traditional cello has a [[spruce]] top, with [[maple]] for the back, sides, and neck. Other woods, such as [[Populus|poplar]] or [[willow]], are sometimes used for the back and sides. Less expensive cellos frequently have tops and backs made of [[Plywood|laminated wood]]. Laminated cellos are widely used in elementary and secondary school orchestras and [[youth orchestra]]s, because they are much more durable than carved wood cellos (i.e., they are less likely to crack if bumped or dropped) and they are much less expensive.

The top and back are traditionally hand-carved, though less expensive cellos are often machine-produced. The sides, or ribs, are made by heating the wood and bending it around forms. The cello body has a wide top bout, narrow middle formed by two C-bouts, and wide bottom bout, with the [[bridge (instrument)|bridge]] and [[F holes]] just below the middle. The top and back of the cello have a decorative border inlay known as [[purfling]]. While purfling is attractive, it is also functional: if the instrument is struck, the purfling can prevent cracking of the wood. A crack may form at the rim of the instrument but spreads no further. Without purfling, cracks can spread up or down the top or back. Playing, traveling and the weather all affect the cello and can increase a crack if purfling is not in place.

The fingerboard and pegs on a cello are generally made from [[ebony]], as it is strong and does not wear out easily.<ref>{{Cite web|title=Cello Construction: How Cellos Are Made {{!}} Johnson String Instrument|url=https://www.johnsonstring.com/cellos-facts/CelloConstruction.htm|access-date=2021-07-02|website=www.johnsonstring.com}}</ref>

===Alternative materials===
In the late 1920s and early 1930s, the [[Alcoa|Aluminum Company of America (Alcoa)]] as well as German luthier G.A. Pfretzschner produced an unknown number of aluminum cellos (in addition to aluminum double basses and violins).<ref>{{Cite book|url=https://books.google.com/books?id=r8zTDQAAQBAJ|title=Aluminum in America: A History|last=R. Skrabec|first=Quentin|publisher=McFarland|year=2017|isbn=9781476625645|pages=88}}</ref> Cello manufacturer [[Luis and Clark|Luis & Clark]] constructs cellos from [[carbon fibre]]. Carbon fibre instruments are particularly suitable for outdoor playing because of the strength of the material and its resistance to humidity and temperature fluctuations. Luis & Clark has produced over 1000 cellos, some of which are owned by cellists such as [[Yo-Yo Ma]]<ref>{{cite web |url=https://www.nytimes.com/2009/01/19/arts/music/19carb.html?_r=0 |title=Cold Case: Luis and Clark Carbon Expedition for Yo-Yo Ma? |newspaper=The New York Times |date=January 18, 2009 |author=Chris Museler |access-date=October 4, 2016}}</ref> and [[Josephine van Lier]].<ref>{{cite web|last1=van Lier|first1=Josephine|title=Luis and Clark Carbon Fibre Cells|url=http://www.albertastringassociation.ca/docs/ASANewsletterSummer2006.pdf|website=Alberta String Association|access-date=4 October 2016|archive-url=https://web.archive.org/web/20140407090955/http://www.albertastringassociation.ca/docs/ASANewsletterSummer2006.pdf|archive-date=April 7, 2014|date=2006}}</ref>

===Neck, fingerboard, pegbox, and scroll===
Above the main body is the carved neck. The neck has a curved cross-section on its underside, which is where the player's thumb runs along the neck during playing. The neck leads to a [[pegbox]] and the [[scroll (music)|scroll]], which are all normally carved out of a single piece of wood, usually [[maple]]. The [[fingerboard]] is glued to the neck and extends over the body of the instrument. The fingerboard is given a curved shape, matching the curve on the bridge. Both the fingerboard and bridge need to be curved so that the performer can bow individual strings. If the cello were to have a flat fingerboard and bridge, as with a typical guitar, the performer would only be able to bow the leftmost and rightmost two strings or bow all the strings. The performer would not be able to play the inner two strings alone.

The [[Nut (instrumental)|nut]] is a raised piece of wood, fitted where the fingerboard meets the pegbox, in which the strings rest in shallow slots or grooves to keep them the correct distance apart. The pegbox houses four tapered [[tuning peg]]s, one for each string. The pegs are used to tune the cello by either tightening or loosening the string. The pegs are called "friction pegs", because they maintain their position by friction. The scroll is a traditional ornamental part of the cello and a feature of all other members of the [[violin family]]. [[Ebony]] is usually used for the tuning pegs, fingerboard, and nut, but other hardwoods, such as [[Buxus|boxwood]] or [[rosewood]], can be used. Black fittings on low-cost instruments are often made from inexpensive wood that has been blackened or "ebonized" to look like [[ebony]], which is much harder and more expensive. Ebonized parts such as tuning pegs may crack or split, and the black surface of the fingerboard will eventually wear down to reveal the lighter wood underneath.

===Strings===
Historically, cello [[String (music)|strings]] had cores made out of [[catgut]], which, despite its name, is made from sheep or goat intestines. Most modern strings used in the 2010s are wound with metallic materials like [[aluminum]], [[titanium]] and [[chromium]]. Cellists may mix different types of strings on their instruments. The pitches of the open strings are C, G, D, and A (black note heads in the playing range figure above), unless alternative tuning ([[scordatura]]) is specified by the composer. Some composers (e.g. [[Ottorino Respighi]] in the final movement of ''[[The Pines of Rome]]'') ask that the low C be tuned down to a B-flat so that the performer can play a different low note on the lowest open string.

===Tailpiece and endpin===
The [[tailpiece]] and [[endpin]] are found in the lower part of the cello. The tailpiece is the part of the cello to which the "ball ends" of the strings are attached by passing them through holes. The tailpiece is attached to the bottom of the cello. The tailpiece is traditionally made of [[ebony]] or another hardwood, but can also be made of [[plastic]] or [[steel]] on lower-cost instruments. It attaches the strings to the lower end of the cello and can have one or more fine tuners. The fine tuners are used to make smaller adjustments to the pitch of the string. The fine tuners can increase the tension of each string (raising the pitch) or decrease the tension of the string (lowering the pitch). When the performer is putting on a new string, the fine tuner for that string is normally reset to a middle position, and then the peg is turned to bring the string up to pitch. The fine turners are used for subtle, minor adjustments to pitch, such as tuning a cello to the oboe's 440&nbsp;Hz A note or tuning the cello to a piano.

The endpin or spike is made of wood, metal, or rigid carbon fiber and supports the cello in playing position. The endpin can be retracted into the hollow body of the instrument when the cello is being transported in its case. This makes the cello easier to move about. When the performer wishes to play the cello, the endpin is pulled out to lengthen it. The endpin is locked into the player's preferred length with a screw mechanism. The adjustable nature of endpins enables performers of different ages and body sizes to adjust the endpin length to suit them.  In the Baroque period, the cello was held between the calves, as there was no endpin at that time. The endpin was "introduced by [[Adrien Servais]] {{circa}} 1845 to give the instrument greater stability".<ref name="hist">{{cite book|last=Stowell|first=Robin|title=The Cambridge Companion to the Cello|url=https://books.google.com/books?id=TvlhQgAACAAJ|date=June 28, 1999|publisher=Cambridge University Press|isbn=978-0-521-62101-4}}</ref> Modern endpins are retractable and adjustable; older ones were removed when not in use. (The word "endpin" sometimes also refers to the button of wood located at this place in all instruments in the violin family, but this is usually called "tailpin".<ref>{{cite news |url=https://www.britannica.com/art/stringed-instrument |title=Stringed instrument |newspaper=Encyclopedia Britannica |author=Eric Halfpenny |author2=Theodore C Grame |access-date=October 4, 2016}}</ref>) The sharp tip of the cello's endpin is sometimes capped with a rubber tip that protects the tip from dulling and prevents the cello from slipping on the floor. Many cellists use a rubber pad with a metal cup to keep the tip from slipping on the floor. A number of accessories exist to keep the endpin from slipping; these include ropes that attach to the chair leg and other devices.

===Bridge and f-holes===
[[File:Cello bridge2.JPG|right|thumb|The bridge of a cello, with a mute (the mute is not in use)]]
The [[bridge (instrument)|bridge]] holds the strings above the cello and transfers their vibrations to the top of the instrument and the soundpost inside (see below). The bridge is not glued but rather held in place by the tension of the strings. The bridge is usually positioned by the cross point of the "f-hole" (i.e., where the horizontal line occurs in the "f"). The [[sound-hole|f-holes]], named for their shape, are located on either side of the bridge and allow air to move in and out of the instrument as part of the sound-production process. The f-holes also act as access points to the interior of the cello for repairs or maintenance. Sometimes a small length of rubber hose containing a water-soaked sponge, called a Dampit, is inserted through the f-holes and serves as a humidifier. This keeps the wood components of the cello from drying out.

===Internal features===
Internally, the cello has two important features: a [[bass bar]], which is glued to the underside of the top of the instrument, and a round wooden [[sound post]], a solid wooden cylinder which is wedged between the top and bottom plates. The bass bar, found under the bass foot of the bridge, serves to support the cello's top and distribute the vibrations from the strings to the body of the instrument. The soundpost, found under the treble side of the bridge, connects the back and front of the cello. Like the bridge, the soundpost is not glued but is kept in place by the tensions of the bridge and strings. Together, the bass bar and sound post transfer the strings' vibrations to the top (front) of the instrument (and to a lesser extent the back), acting as a [[diaphragm (acoustics)|diaphragm]] to produce the instrument's sound.

===Glue===
Cellos are constructed and repaired using [[hide glue]], which is strong but reversible, allowing for disassembly when needed. Tops may be glued on with diluted glue since some repairs call for the removal of the top. Theoretically, hide glue is weaker than the body's wood, so as the top or back shrinks side-to-side, the glue holding it lets go and the plate does not crack. Cellists repairing cracks in their cello do not use regular [[wood glue]], because it cannot be steamed open when a repair has to be made by a [[luthier]].

===Bow===
[[File:Bow hand Violoncello.jpg|thumb|right|upright=0.7|A cello French bow<ref>As opposed to the German bow popular in baroque era, held underhand.</ref> ''sul ponticello'']]
Traditionally, [[bow (music)|bows]] are made from [[Paubrasilia|pernambuco]] or [[brazilwood]]. Both come from the same species of tree (''Caesalpinia echinata''), but Pernambuco, used for higher-quality bows, is the heartwood of the tree and is darker in color than brazilwood (which is sometimes stained to compensate). Pernambuco is a heavy, resinous wood with great elasticity, <!--and high sound velocity-->which makes it an ideal wood for instrument bows. Horsehair is stretched out between the two ends of the bow. The taut horsehair is drawn over the strings, while being held roughly parallel to the bridge and perpendicular to the strings, to produce sound. A small knob is twisted to increase or decrease the tension of the horsehair. The tension on the bow is released when the instrument is not being used. The amount of tension a cellist puts on the bow hair depends on the preferences of the player, the style of music being played, and for students, the preferences of their teacher.

Bows are also made from other materials, such as carbon fibre—stronger than wood—and fiberglass (often used to make inexpensive, lower-quality student bows). An average cello bow is {{convert|73|cm|in|abbr=on}} long (shorter than a violin or viola bow) {{convert|3|cm|in|abbr=on}} high (from the frog to the stick) and {{convert|1.5|cm|in|abbr=on}} wide. The frog of a cello bow typically has a rounded corner like that of a viola bow, but is wider. A cello bow is roughly {{convert|10|g|oz|abbr=on}} heavier than a viola bow, which in turn is roughly {{convert|10|g|oz|abbr=on}} heavier than a violin bow. <!-- for example, see http://www.codabow.com/info_buyfirstbow.html -->

Bow hair is traditionally [[horsehair]], though synthetic hair, in varying colors, is also used. Prior to playing, the musician tightens the bow by turning a screw to pull the frog (the part of the bow under the hand) back and increase the tension of the hair. [[Rosin]] is applied by the player to make the hair sticky. Bows need to be re-haired periodically. [[Baroque]]-style (1600–1750) cello bows were much thicker and were formed with a larger outward arch than modern cello bows. The inward arch of a modern cello bow produces greater tension, which in turn produces a louder sound.

The cello bow has also been used to play [[electric guitar]]s. Jimmy Page pioneered its application on tracks such as "[[Dazed and Confused (Jake Holmes song)|Dazed and Confused]]". The [[post-rock]] [[Icelanders|Icelandic]] band [[Sigur Rós]]'s lead singer often plays guitar using a cello bow.

In 1989, the German cellist [[Michael Bach (musician)|Michael Bach]] began developing a [[curved bow]], encouraged by [[John Cage]], [[Dieter Schnebel]], Mstislav Rostropovich and [[Luigi Colani]]: and since then many pieces have been composed especially for it. This curved bow (''BACH.Bow'') is a convex curved bow which, unlike the ordinary bow, renders possible polyphonic playing on the various strings of the instrument. The BACH.Bow is particularly well-suited to the solo repertoire for violin and cello by J. S. Bach; which requires both polyphonic and monophonic playing.  

[[File:Michael Bach, Cello with BACH.Bow.jpg|thumb|Michael Bach, cello with [[curved bow|BACH.Bow]]]]