To use a capo, clamp it across the fretboard at the fret that raises the pitch to the key you want, just behind the fret wire, with even pressure on all six strings. A capo on the 2nd fret raises every chord by a whole tone, so a G shape sounds as A major.
How do you use a capo?
A capo is a clamp that presses all six strings down at a chosen fret, acting like a movable nut that shortens the strings and raises their pitch. Put a capo on the 2nd fret and every open chord shape sounds two semitones higher: a G shape sounds as A major, a C shape sounds as D major, and an E shape sounds as F# major. The shapes under your fingers stay the same, but the key changes, which is why the capo is the guitarist's transposing tool. The capo is used for two main reasons: to change the key of a song without changing the chord shapes, and to make a song easier to play by using open shapes in a key that would otherwise need barre chords. A song in Eb major needs barre chords, but with a capo on the 3rd fret you can play it with C shapes, which are open and easy. A singer who wants a song a little higher can move the capo up a fret or two, instead of learning the song in a new key. The capo calculator works out which fret to use for any key, and the capo chart shows the chord each shape makes at each fret.
How a capo works
A capo works by shortening the vibrating length of the strings, which raises their pitch by the same amount on every string. Each fret raises the pitch by one semitone, so a capo on the 1st fret raises every string by one semitone, a capo on the 2nd fret raises them by two semitones, and so on. The open strings become the new nut: the string that was open E becomes F at the 1st fret, F# at the 2nd fret, and G at the 3rd fret. The fretted notes move up by the same amount, so a chord shape that was G major becomes A major at the 2nd fret, because every note of the shape has moved up by two semitones. Placing the capo correctly matters as much as choosing the fret. Put it just behind the fret wire, not in the middle of the fret, and close to the fret, so the strings are pressed down firmly without buzzing. If the capo is too far from the fret, the strings will buzz; if it is too close to the fret, it can pull the strings sharp. The pressure should be even: a capo that is too tight will pull the strings sharp and make the guitar sound out of tune, while a capo that is too loose will let the strings buzz. The G major guitar chord becomes A major with a capo on the 2nd fret, and the C major guitar chord becomes D major.
Worked example — playing in Eb with a capo. Eb major is a hard key on guitar, because its chords, Eb, Fm, Gm, Ab, Bb, Cm and Ddim, are mostly barre chords. Put a capo on the 3rd fret and play C shapes instead: a C shape sounds as Eb major, an F shape sounds as Ab major, and a G shape sounds as Bb major, because the capo raises every shape by three semitones. The key of Eb major lists the chords, and the C, F and G shapes are the open chords that replace them. Check the maths: C plus three semitones is Eb, F plus three semitones is Ab, and G plus three semitones is Bb, which are the I, IV and V chords of Eb major.
How to practise with a capo
Practise the capo by playing the same song at several capo positions, so you learn to hear the key change without changing the shapes.
- Play the I–V–vi–IV progression in C major with no capo, then with a capo on the 2nd fret, and listen for the key rising to D major.
- Play a G shape with a capo on the 2nd, 4th and 5th frets in turn, and name the chord it makes each time: A major, B major and C major.
- Take a song in Eb major and play it with a capo on the 3rd fret using C shapes, checking that the chords sound right.
- Practise placing the capo quickly and cleanly, just behind the fret wire, so you can move it between songs without a long pause.
- Use the capo calculator to find the capo fret for any key, and check your answer by playing the shapes.
Common mistakes
- Putting the capo in the middle of the fret — A capo in the middle of a fret will buzz, because the strings are not pressed firmly against the fret wire. Put the capo just behind the fret wire, close to it, so the strings are held down cleanly.
- Using too much pressure — A capo that is too tight pulls the strings sharp, especially on a lightly built guitar, and the guitar will sound out of tune. Use just enough pressure to stop the buzzing, and no more.
- Forgetting to retune — Putting a capo on can pull the strings slightly sharp, so check your tuning after you place the capo, and retune if necessary, especially on the low E string.
Quick reference
This table shows what three common open chord shapes sound as at each capo fret, so you can work out which fret to use for any key. Read across a row to see the chord each shape makes at that fret, and read down a column to see how one shape moves up the neck as the capo moves.
| Capo fret | C shape sounds as | G shape sounds as | D shape sounds as |
|---|---|---|---|
| No capo | C major | G major | D major |
| 1st fret | C# major | G# major | D# major |
| 2nd fret | D major | A major | E major |
| 3rd fret | D# major | A# major | F major |
| 4th fret | E major | B major | F# major |
| 5th fret | F major | C major | G major |
| 7th fret | G major | D major | A major |
Use the table to find the capo fret for a key you want to play in: find the key in the table, look at which shape makes it, and put the capo on the fret in the first column. When you can read the table without looking, try the same exercise with E and A shapes, and build your own capo chart for them.
Frequently asked questions
How do I use a capo on a guitar?
Clamp it across the fretboard at the fret that raises the pitch to the key you want, just behind the fret wire, with even pressure on all six strings. A capo on the 2nd fret raises every chord by a whole tone, so a G shape sounds as A major.
What fret should I put the capo on?
It depends on the key you want and the shapes you want to use. To play in D major with C shapes, put the capo on the 2nd fret; to play in Eb major with C shapes, put it on the 3rd fret. The capo calculator works it out for any key.
Does a capo change the key of a song?
Yes. A capo raises the pitch of every string by the same number of semitones, so the whole song moves up by that interval. A song in C major with a capo on the 2nd fret sounds in D major, even though the shapes are still C shapes.
Can I use a capo on any guitar?
Yes, on acoustic, electric and classical guitars, although classical guitars need a wider capo for their flat fretboard. The capo must match the width and the curve of the fretboard, or it will not press all the strings evenly.
Do I need to retune after putting on a capo?
Usually, yes, at least a check. A capo can pull the strings slightly sharp, especially if it is too tight, so check your tuning after you place it, and retune if necessary.