A capo is a clamp that holds the strings down against one fret, so that fret behaves like a new nut. Everything above it stops sounding, the open strings now vibrate from the capo to the bridge, and every open string sounds higher by the same number of semitones as the fret you chose. Chord shapes stay the same; the key moves. That is the whole idea, and it is old enough that capo patents were being granted in the nineteenth century.
The details are where players get into trouble. Capos differ in how they clamp, how much pressure they need, how fast they move and whether they cover all six strings or only some of them. Capos combined with open and alternate tunings are covered in our open and alternate tunings guide, so we do not repeat that material here.
Quick Facts
What a Capo Actually Does
On an unclamped guitar the nut sets the top end of the vibrating length of each open string. The Concise Oxford Dictionary of Music, in the entry reproduced on Encyclopedia.com, defines the nut that way and adds that a movable device that can be placed along the strings is sometimes used, especially in guitar playing. The same entry notes that in the United States the word “capotasto” is reserved for this movable type. A capo is that movable nut.
Two of the oldest descriptions we could read in full are patents. James Ashborn’s 1850 patent says the capo fixes the vibrating length of the strings so the instrument can be set for playing in difficult keys. Willard H. Russell’s patent, filed in 1927 and granted in 1931, describes a removable device for changing the key.
Two things follow from the geometry. First, the pitch rise is the same on every covered string, so the relationships between the open strings stay the same; the guitar is effectively the same instrument tuned higher. Second, the vibrating length from capo to bridge is shorter than the full scale. Our Taylor GS Mini guide argues that the lighter tension of that guitar’s shorter scale makes capo work more comfortable; that is our site’s reading, not a measured figure.
Capo Types
The names below are the ones makers use on their pages.
Trigger (Spring-Clamp) Capos
D’Addario’s guide describes the process: squeeze the arms, set the capo on the chosen fret, release, and adjust the pressure if the design allows it. D’Addario adds that trigger capos can clip to the headstock when they are not in use. In our view the trade-off is speed against fine control: a spring sets the pressure unless the model offers an adjuster.
Screw and Micrometer Capos
These use a tension screw or knob instead of a spring. D’Addario says screw capos sit lower and take longer to apply and remove than trigger capos, and that they are good for compact storage. Its own micrometer capos adjust tension with a knob that you turn until the open strings ring without buzz.
Cradle Capos
D’Addario describes cradle capos as a premium option that rests on the neck behind the nut, with a self-centering design that applies even pressure across all strings to prevent buzz. G7th, a maker that sells several capo styles, lists a range that includes the Performance 3, Heritage, Newport, Nashville and UltraLight models, with adjustable tension on several of them. G7th says its Unique Tension Control mechanism allows fast adjustment and improves tuning stability, and that a string pad design it calls ART (Adaptive Radius Technology), introduced in 2016, improves tuning stability further. Those are the maker’s own claims.
Elastic Strap Capos
In Russell’s patent, a soft rubber block presses on the strings, a rigid plate reinforces it, and an elastic strip wraps around the neck. Tension is set by choosing among several eyelets on the strip, so the same device fits different neck sizes.
Lever, Roller and Strap-Plate Designs
The 1850 Ashborn patent, titled “Guitar-head and capo tasto” on Google Patents, is a different mechanism from either a spring or an elastic strip. It uses a pressure plate on a metal strap that wraps down both sides of the neck, with a buckskin-covered eccentric roller acting on the underside of the neck. Turning the roller half way releases the plate, so the device can be pushed back beyond the last fret. The Russell patent also presses a padded block onto the strings and holds it with a strip around the neck.
Per-String and Universal Capos
The SpiderCapo is built from individual fingers on a shaft. According to its maker’s FAQ, you position it across the neck and tighten a knob, and you can remove fingers to use fewer than six, leaving the other strings open. The FAQ says the capo works on classical, electric and both steel- and nylon-string acoustic guitars, and that it can work on fanned-fret guitars if you reverse up to three of the fingers. For 12-string guitars the FAQ gives a workaround: cover the grooves in the finger with black electrical tape on the three lower courses, where the two strings differ in thickness.
Interchangeable-Radius Designs
The partialcapo.com site, a site about partial capos, lists the Thalia as a spring clamp with a removable rubber foot and interchangeable radii. That is the site’s description; we did not read the maker’s own page.
How to Place a Capo
D’Addario’s advice is to put the capo directly behind the fret, not between frets and not on top of the fret. It compares this to fretting with your own finger, which gives a clear tone without buzzing or rattling.
Pressure is the second variable. D’Addario says too little pressure makes the strings buzz and lose tone, while too much pulls them out of tune, and that the right amount is the point where the strings ring open cleanly. In our view, check the tuning after the capo is on, since the guitar was tuned without it.
Not every design follows the same rule. SpiderCapo’s FAQ says placing a finger’s forward tab behind the fret allows some tuning variability as you slide the finger along the string, and placing it in front of the fret gives the most precise intonation. That is advice for that capo’s design, where each finger sits on one string and can be nudged, not a general instruction. For a standard full-width capo, D’Addario’s behind-the-fret guidance is the one to follow.
Tuning Problems and What Causes Them
The sources we opened name pressure and placement as the causes of capo-related tuning trouble, and we add our own note on retuning.
Pressure. Covered above. A capo that is tighter than it needs to be can pull the strings out of tune, according to D’Addario.
Position. D’Addario’s guidance is to sit directly behind the fret, not on top of it or between frets. SpiderCapo’s FAQ adds that placement changes how much tuning variability you get on its per-string design.
Retuning with the capo on. In our view, tune after you place the capo, and again if you move it to a different fret.
Partial Capos and Open Tunings
A partial capo clamps only some of the strings, so the others ring open. Gayla Drake’s January 2010 round-up in Premier Guitar sorted partial capos into fixed, adjustable and what she called “special” designs. Fixed capos, such as the Kyser K’Lever and a Shubb DADGAD-style model she tested, block particular strings so that the guitar sounds as if it were in a different tuning. The Third Hand and the Creative Tunes Spider Capo were her adjustable examples, covering all strings and letting you choose which stay open.
Drake’s key point is that a partial capo gives an open-tuning sound while the guitar stays in standard tuning, but the chord shapes do not become open-tuning shapes. With DADGAD- or Open G-style capos, only the open voice sounds like the altered tuning; the rest of the chords stay as they are in standard tuning. She was sceptical for players who want what open tunings really offer, which is voicings that are not available across the neck in standard tuning. She presented partial capos instead as a way to get an open-tuning flavour without learning a new tuning.
The Third Hand’s maker describes it differently: as the first partial capo, and still the most universally useful, because it can clamp any combination of strings at any fret on any guitar. According to the maker, it works because it changes the length of an open string rather than retuning it, so the scale and chord geometry stay the same. The maker’s page says production ran from 1980 to 2015 and that it is discontinued; the company still sells Liberty FLIP capos. A second site, partialcapo.com, says the design has been “unchanged since 1976”; we could not resolve that date against the maker’s 1980, so we give both. That site also says the Third Hand has 63 possible clamping combinations at each fret, which is the number of ways to choose at least one of six strings. Drake found it the lowest-tech capo in her test, noted that it is not a quick change, and said the elastic may wear out and need replacing every couple of years.
Our tunings guide covers the real tunings and has its own section on capos. Drake’s round-up also covers Bob Kilgore’s Harmonic Capo, which produces harmonics and which she treats as a separate kind of tool, not an altered-tuning device.
One related idea, in our view: a capo on a guitar tuned down gets you back to the original key. If you tune a whole step down and put a capo on the second fret, the open strings sound where they did in standard tuning. That is simple arithmetic, and it is worth knowing before you decide whether to tune down or capo up.
Capos on 12-Strings, Baritones and Headless Guitars
G7th lists a 12-string range among its categories, and SpiderCapo’s FAQ describes a tape workaround for the lower courses, where the two strings differ in thickness. Our electric 12-string guide covers the instrument itself.
Baritone guitars have longer scales than standard guitars, a subject our baritone guitars guide covers; the capo principle is the same. A related point appears in our Steinberger and headless guitars guide, where, as that guide reports it, Guitar.com’s Justin Beckner compares the TransTrem locking in position to a capo. That is Beckner’s comparison, and the guide is the place to read it in context.
History
The earliest dated capo document we could open is a US patent. James Ashborn of Walcottville, Connecticut, received US Patent 7,279 on April 16, 1850, according to Google Patents. The patent covers a tuning head that uses cords in place of geared keys and an improved capo. Ashborn’s capo is the design described above, with a strap-mounted plate and an eccentric roller. We call it an early documented patent, not the first capo, because we did not search earlier non-US documents.
There is older evidence for movable devices that is not patent-based, but it is thin. The Finely Strung blog, a diary about making stringed instruments, says some early instruments had holes drilled through the fingerboard and neck so that a capo could be held with a screw and wing nut. It cites an English guittar made in London in 1760 at the Ashmolean Museum, Oxford, as an example. That is one blog citing one object; treat it as a lead, not a settled date. The same post describes the cejilla as a capo with a long history that is mainly used today by flamenco guitarists, but it does not give an origin date, and we could not find an opened source for the commonly repeated claim of Spanish origin, so we do not make it. Our Paco de Lucia guide covers flamenco guitar more broadly.
The elastic-strap design has its own patent record. Willard H. Russell, of Los Angeles, filed US 1,788,636, titled “Capo tasto,” on October 29, 1927, and it was granted on January 13, 1931. Google Patents lists the inventor as Willard H. Russell, while some secondary sources call him William or “Bill” Russell, so we use the name on the patent record. On partial capos, the Third Hand maker dates its own production to 1980, which is the earliest partial-capo date we can document from a maker page.
Who Uses One
We name players only where a source we opened says so. Our Billy Strings guide lists “Elliott” under capos, according to Premier Guitar’s 2023 rig rundown as that guide cites it; we have not independently re-checked that rundown, so treat it as reported. The Yamaha FG800 guide mentions a capo in its accessories FAQ as a way to play songs in different keys without relearning chord shapes.
Choosing One
In our view:
- If you change capo position often, a trigger-style capo is the quick option, with the trade-off that you may need to retune.
- If you want to set the pressure once and leave it, a screw or micrometer capo gives more control.
- If you want open-tuning colours without retuning, a partial capo is the place to start, with the caveat Drake gives about chord shapes.
- If you play a 12-string or a fanned-fret guitar, check the maker’s own page for compatibility.
Frequently Asked Questions
Does a capo change the sound of the guitar?
Yes. It shortens the vibrating length of every covered string, so the pitch rises. The chord shapes do not change, only the key.
Where exactly should a capo go?
Directly behind the fret you want, not on top of it and not mid-way between frets, according to D’Addario. Some per-string designs, such as the SpiderCapo, have their own guidance.
Why does my guitar sound out of tune with a capo on?
D’Addario names too much pressure, which can pull the strings out of tune. Check the placement behind the fret, then retune with the capo on.
What is a partial capo?
A capo that clamps only some strings so the others ring open. Premier Guitar’s 2010 round-up says it gives an open-tuning sound while the guitar stays in standard tuning, without making the chord shapes open-tuning shapes.
What is a cejilla?
The Finely Strung blog describes it as a capo with a long history that flamenco guitarists mainly use today. We could not source a firm origin date or place for it.
Is a capo bad for the guitar?
None of the sources we opened says so. D’Addario’s concern is pressure and tuning, not damage. SpiderCapo’s FAQ does tell users to keep the end tabs on the fingerboard, not the side of the neck, to avoid marks.
