View source for Tuning mechanisms for stringed instruments

{{short description|Different types of stringed instrument parts and their methods for tuning stringed instruments}}
{{More citations needed|date=October 2013}}
[[Image:Peg in box.jpg|thumb|[[Violin]] pegbox, retouched image]]
[[File:A Medieval - Post Medieval tuning peg made from animal skeletal material, probably bone. (FindID 551578).jpg|thumb|Medieval bone tuning pin. One end is pierced for the string; the other is squared off to fit in a tuning lever socket. The middle section, which would pass through the wood, is tapered.]]

A variety of methods are used to [[Musical tuning|tune]] different [[String instrument|stringed instruments]]. Most change the [[Pitch (music)|pitch]] produced when the string is played by adjusting the [[Tension (physics)|tension]] of the [[Vibrating string|strings]].

A '''tuning peg''' in a [[#Pegbox|pegbox]] is perhaps the most common system. A peg has a grip or knob on it to allow it to be turned. A '''tuning pin''' is a tuning peg with a detachable grip, called a [[tuning lever]]. The socket on the tuning lever fits over the pin and allows it to be turned. Tuning pins are used on instruments where there is no space for a knob on each string, such as pianos and harps.

Turning the peg or pin tightens or loosens the string. Some tuning pegs and pins are tapered, some threaded. Some tuning pegs are ornamented with [[Exoskeleton|shell]], metal, or plastic inlays, beads (pips) or rings.

Other tuning systems include '''screw-and-lever tuners''', '''geared tuners''', and the '''konso''' friction tuning system (using braided leather rings).

==Pegbox or headstock==
{{anchor|Pegbox}}
A '''pegbox''' is the part of certain [[String instrument|stringed]] [[musical instruments]] (the [[violin family]]: [[violin]], [[viola]], [[cello]], [[double bass]]) that houses the tuning pegs. The corresponding part of the [[lute]] family (including [[guitar]], [[mandolin]], [[banjo]], [[ukulele]]) is called the ''[[headstock]]''.

==Tapered pegs and pins==
[[File:Khmer instruments 05.jpg|thumb|left|Tuning pegs on a [[tro (instrument)|tro]]]]
A tapered peg is simply a smooth peg with a string wound around it. The tension of the string is controlled by turning the peg, and the peg is held in place by friction in its hole (in contrast to [[machine head|tuning machines]], below).

A properly working peg will turn easily and hold reliably, that is, it will neither stick nor slip. Modern pegs for [[violin]] and [[viola]] have conical shafts, turned to a 1:30 taper, changing in diameter by 1&nbsp;mm over a distance of 30&nbsp;mm. Modern [[cello]] pegs have a slightly more aggressive 1:25 taper. 19th century and earlier pegs, for use with stretchier gut strings, typically had an even steeper taper of 1:20.

The taper allows the peg to turn more easily when pulled out slightly, and to hold firmly when pushed in while being turned. Since the typical wear pattern on a peg shaft interferes with this action, pegs occasionally require refitting, a specialized job which amounts to reshaping both pegs and holes to a smooth circular conical taper.

Tapered tuning pins are similar, but must be turned with a tuning tool, usually called a [[tuning key]], tuning lever, or tuning wrench. Historically, pins were also tapered (see image of bone peg, right), but they are now generally threaded, instead (see below).

<gallery>
File:Tuning peg.png|A modern [[violin]] tuning peg, not yet shaved to fit an instrument. Note smooth taper and finger grip.
File:Tromba marina Musikmuseum Basel 24102013 03.jpg|The single tuning peg of a [[tromba marina]], turned by hand
File:Jade Tuning Pegs.jpg|Ornate jade tuning pins on a [[guqin]]
File:Tuning key for qin (guqin, stringed instrument), China, Han dynasty, 201 BC to 221 AD, gilded bronze - Östasiatiska museet, Stockholm - DSC09663.JPG|Gilded bronze [[tuning key]] for turning the pins of a [[guqin]], [[China]], [[Han dynasty]], 201 BC to 221 AD.
File:Medieval_Key_(Musical)_(FindID_623900).jpg|A medieval tuning key with a square socket, for turning tuning pins. Excavated in [[Nottinghamshire]], [[Great Britain]].
File:Patton_Queen_Mary_Harp_Replica.JPG|Brass tuning pins on a replica of the late medieval [[Queen Mary Harp]].
File:Oud-cordier.png|pegbox and pegs of an [[oud]].
</gallery>

===Use===
[[File:Tuning Pegs (Kunti) of Saraswati Veena.jpg|thumb|Tuning pegs with knobs on a [[veena]].]]
Tapered pegs are a simple, ancient design, common in many musical traditions.

Tapered pegs are common on classical [[List of Indian musical instruments|Indian instruments]] such as the [[sitar]], the [[Saraswati veena]], and the [[sarod]], but some like the [[esraj]] and [[Mohan veena]] often use modern tuning machines instead. Tapered pegs are also used on older European instruments, such as the Bulgarian [[gadulka]] and the [[hurdy-gurdy]], as well as on [[flamenco guitar]]s.

Among modern Western musical instruments, tapered pegs are most often used on [[violin family]] instruments, though usually the [[double bass]] uses tuning machines.

===Peg dope===
<!--[[Peg dope]] redirects directly here.-->
[[Image:Peg compound.JPG|thumb|left|Two types of compound; bearing surfaces of peg are visible as shiny bands]]

'''"Peg dope"''' (also '''peg paste''', '''peg stick''', '''peg compound''') is a substance used to coat the bearing surfaces<ref>{{cite web |url=http://www.lutherie.net/care.html |title=String Instrument Care |author=Paul Hostetter |access-date=8 September 2010 |quote=Pegs are tapered, and must contact the insides of the holes on both sides of the pegbox. The fit is very important, of course, as is the nature of the contacting surfaces there. Raw wood on raw wood never works well, so a preparation is usually applied to facilitate a smooth turning of the peg. }}</ref> of the tapered tuning pegs of [[string instrument]]s (mainly [[violin]]s, [[viola]]s, [[cello]]s, [[viol]]s and [[lute]]s ). Manufactured varieties are generally sold in either a small stick (resembling [[lipstick]]), a block, or as a liquid in a bottle. Commonly used home expedient treatments may include soap, graphite, or talc.

Peg dope serves two different (and almost conflicting) purposes. It both lubricates the peg shaft so it turns easily in the [[#Pegbox|pegbox]] and provides friction to keep the pegs from slipping with the force of [[Vibrating string|string]] tension. Tuning pegs that are well fitted and properly doped will both turn smoothly throughout an entire rotation and hold firmly wherever the player wishes.

Without the proper amount of friction to hold the peg in place, a tapered tuning peg will tend to "slip", making a tuning setting virtually impossible to maintain. String instruments with pegs that are slipping can be tuned briefly, but will be [[Musical tuning#Tuning practice|out of tune]] within minutes as soon as the peg slips again. With too much friction, adjusting the tuning at all is impossible. If the pegs or their holes are not perfectly round, or if the bearing surfaces of the pegs are indented from wear, peg dope will not remedy the resulting problems.

==Threaded pegs and pins==
Some pegs and pins are threaded with a shallow, [[fine adjustment screw|fine thread]]. They are not tapered, but straight, and they go into straight-sided holes.

Like tapered pins, threaded pins must be set in a pin block of fairly hard wood, such as [[cherry wood|cherry]] or [[white oak]], or they will not stay in tune well.<ref>{{cite web |url=http://www.sligoharps.com/8book.pdf |title=Chapter 8. Fabricating the Neck and Pillar|format=Book chapter|website=sligoharps.com|access-date=1 February 2023}}</ref> Some pin block woods come from endangered trees.<ref>{{cite web |url=https://www.wood-database.com/wood-articles/restricted-and-endangered-wood-species/ |title = Restricted and Endangered Wood Species {{!}} The Wood Database}}</ref> Some specialized plywoods can also be used (piano pin block stock or the die maker's ply used for [[rotary die]]s).<ref>{{cite web|url=http://www.sligoharps.com/2book.pdf+|title=Chapter 2. Creating, Buying, Borrowing or Stealing a Design|format=Book Chapter|website=sligoharps.com|access-date=1 February 2023}}</ref> 

Threaded tuners are durable, will take very high string tensions. They do not push outwards on the hole and wedge the wood apart, which can reduce the risk of splitting it. They can be set in [[blind hole]]s, which allows the wood to retain more strength for a given weight.<ref>{{cite web |url=http://folcharp.com/zitherpins.html |url-status=dead |archive-url=https://web.archive.org/web/20080724215944/http://www.folcharp.com/zitherpins.html |archive-date=2008-07-24 |title=FolcHarp - Zither pins}}</ref> They can, however, also be set in holes drilled right through the wood, to look like older pins. Threaded pins can be installed with an [[arbor press]], and do not need to be re-set, but should be backed off a few turns when changing a string to keep pin height even.<ref>{{cite web |url=https://manufacturing.dustystrings.com/harps/accessories-hardware/hardware/threaded-tuning-pins |title = Threaded Harp Tuning Pins {{!}} Dusty Strings}}</ref><ref>[https://manufacturing.dustystrings.com/application/files/2014/7516/8049/Replacing_Harp_Strings.pdf Replacing harp strings] {{Dead link|date=February 2022}}</ref>

===Use===
Tuning pins may be known as wrest pins or zither pins, regardless of the instrument on which they are used. They are used on instruments with many close strings, as they are more compact and cheaper. Modern pianos use threaded pins, as do many [[harp]]s, [[psaltry|psaltries]], [[dulcimers]], [[zithers]], and other instruments.

<gallery>
File:Grand piano tuning 01.jpg|The threaded tuning pins on a [[piano]] must be turned with a [[tuning lever]].
File:David Klavins stimmt sein Una Corda Klavier.webm|A one-cord-per-note piano being tuned with a [[tuning lever]].
File:Yatga mechanics.jpg|Tuning pins and tuning lever on a [[yatga]].
File:MuseuMusicaBCN 8970.jpg|[[Harp]]s also carry pins rather than pegs.
File:Clavijas afinacion piano.jpg|Tuning pins usually have square ends, allowing them to be turned with a [[square socket]].
File:TuningWrench.jpg|A modern T-shaped [[tuning wrench]].
File:Stimmhammer Cembalo.JPG|A tuning lever of another shape, like that used on the piano in the earlier image.
</gallery>

==Screw-and-lever tuners==
[[File:FineTuner-pjt.jpg|thumb|upright=1.5|A violin [[tailpiece]]. Here, the two strings on the far side pass through the keyhole slots directly, but the nearer two strings use fine tuners.]]
Fine tuners are used on the [[tailpiece]] of some stringed instruments, as a supplement to the tapered pegs at the other end. Tapered pegs are harder to use to make small adjustments to pitch.

Fine tuners are not geared. They have a screw with a [[knurl]]ed head, whose lower end advances against one end of a lever with a right-angle bend in it. The string is fastened to the other end of the lever, and tightening the screw tightens the string.<ref>{{cite web |url=https://www.violins.ca/info/tune_a_violin_fine_tuners.html |title = How to Install and Use Violin Fine Tuners}}</ref> With the screw at the lower limit of its travel, the lever can come close enough to the instrument's top to pose a risk of scarring it.<ref name=strings_finet>{{cite web |url=http://stringsmagazine.com/how-to-select-the-right-fine-tuners/ |title = How to Select the Right Fine Tuners {{!}} Strings Magazine| date=February 2009 }}</ref> To avoid damage to the top, the screw may be turned out as far as it goes while still engaging the lever, and the string re-tuned using the peg.<ref>{{cite web |url=https://www.dummies.com/art-center/music/violin/troubleshooting-guide-for-dealing-with-violin-pegs-and-fine-tuners/ |title = dummies - Learning Made Easy}}</ref>

Fine tuners can buzz, and may cut strings if not filed smooth before use. They add weight and, when not built into the [[tailpiece]], reduce string afterlength.<ref name=strings_finet/> Fine tuners are common on cellos, but some violinists regard them as an aid for beginners who have not yet learned to tune precisely using pegs alone.<ref>{{cite web |url=http://blog.feinviolins.com/2011/04/fine-tuners.html |title = The Violin Shop: Fine Tuners}}</ref>

==Geared tuners==
{{main|machine head}}

Pegs for [[double bass]] and [[guitar]] family instruments are usually geared, and are called tuning machines or [[machine head]]s. They often use a [[worm gear]]. The [[Gear train#Speed ratio|gearing ratio]] varies; while higher ratios are more sensitive, they are also more difficult to manufacture precisely. Machine heads may be open, with exposed gears, or closed, with a casing around all the gears.

Geared pegs for [[violin family]] instruments also exist, although they have not gained wide use, which has to do with the extensive and irreversible physical modification that must be made to the peg box in order to mount them, which is often viewed as ruining the aesthetics of the instrument, combined with a bad reputation they acquired due to poorly designed early models that were prone to failure, often with catastrophically damaging results.

The most recently marketed pegs of this sort use [[planetary gears]] designed to fit inside a case shaped like a friction peg. They have seen some adoption as they look almost exactly like friction pegs, require no more modification of the instrument than a new set of friction pegs, and make fine tuners unnecessary. They are also durable and less sensitive to changes in temperature and humidity.<ref>{{cite web |title=Information – Perfection pegs |url=https://perfectionpegs.twofold.com.au/information/ |website=perfectionpegs.twofold.com.au |access-date=10 August 2019}}</ref> They are popular on banjos.<ref>{{cite web |title=Banjo Tuning Pegs Planetary vs Geared |url=https://www.folkmusician.com/blogs/blog/banjo-tuning-pegs-planetary-vs-geared |website=Folkmusician |language=en |date=30 March 2018}}</ref>

<gallery mode=packed>
File:Aid for Trade Global Review 2017 – Day 1 Sona Jobarteh tuning kora.jpg|[[Sona Jobarteh]] tuning a [[kora (instrument)|kora]] with open [[machine head]]s
File:Open-tuning-peg-guitar.JPG|An open [[machine head]], detached from the instrument
File:Guitar string tunner.JPG|A closed [[machine head]], detached from the instrument
File:Cambio corde- girare in avanti la meccanica.jpg|Tuning a guitar with closed machine heads
File:Levin classical guitar - tuners (by Anders Ljungberg).jpg|Mounted open machine heads. Note slot in background where the strings are wound around the pin of the tuner.
File:Acoustic guitar tuning pegs (14433071079).jpg|Close-up of the gearing of a mounted open machine head
</gallery>

==Konso==
[[File:Kora-Player2.jpg|thumb|[[Griot|Jali]] Fily Sissokho playing a [[kora (instrument)|kora]] tuned with konso (braided leather ring) string terminations.]]
The konso system is traditionally used on [[kora (instrument)|koras]]. It consists of braided leather rings that wrap around the neck of the instrument. The rings are pulled along the neck of the instrument to change string tension. It can be quick to adjust but requires a fair degree of strength.<ref>{{cite web | url=http://dennishavlena.com/newneck.htm | title=Make an easier-to-tune replacement neck for a leather-ring (Konso) African Kora neck }}</ref>

==See also==
{{Commons category|String instrument tuning}}
* [[Machine head]]

==References==
{{reflist}}

{{Strings (music)}}
{{Violin family}}

[[Category:Guitar parts and accessories]]
[[Category:String instrument construction]]