7. Capo Basics: How and Why to Use One
A capo clamps across all six strings at a chosen fret. Everything behind it becomes your new nut, so every open string rises by however many semitones you clamped up. The shapes in your hands stay exactly the same; only the pitch that comes out changes.
What it is actually for
Fitting a song to a voice. A song in Eb is miserable on guitar and routine for a singer. Put a capo at the 3rd fret, play it with C shapes, and you get Eb without learning a single new chord. This alone is why most people buy one.
Getting open strings in an awkward key. Open strings ring longer and brighter than fretted notes, and barre chords cannot produce that sound at all. A capo lets you keep the chime in keys that would otherwise be all barres.
Two guitars, one song. One player without a capo, one at the 5th fret playing different shapes for the same chords, and the parts interlock instead of doubling. Everything stays in tune with itself because both are playing the same pitches from different places. This is standard practice on acoustic records.
Working out what you are actually playing
Count up from the shape by the capo's fret number. A C shape with the capo at 3 sounds as Eb, because C up three semitones is Eb.
| Capo | C shape | G shape | D shape | Am shape | Em shape |
|---|---|---|---|---|---|
| 1 | C# | G# | Eb | Bbm | Fm |
| 2 | D | A | E | Bm | F#m |
| 3 | Eb | Bb | F | Cm | Gm |
| 4 | E | B | F# | C#m | G#m |
| 5 | F | C | G | Dm | Am |
| 7 | G | D | A | Em | Bm |
The other direction is just as useful. If a chart says Bb and you would rather not barre it, look for a capo position that turns Bb into a shape you like: capo 1 makes it an A shape, capo 3 a G shape, capo 6 an E shape.
Fitting it properly
Most capo problems are placement problems, not capo problems.
- Sit it just behind the fret, in the same place you would put a finger. Too far back and strings buzz; directly on top of the wire and they choke.
- Keep it straight. A capo at an angle presses harder on one side, which pulls those strings sharp.
- Use the least pressure that works. Over-tightening bends strings sideways and pushes the whole guitar sharp — most noticeably on the wound strings.
- Retune after clamping, especially above the 5th fret. It will not be far out, but it will be out.
What it does to the tone
Fretted notes near a capo sound brighter and tighter than the same pitch played further up the neck, because the vibrating string is shorter and under proportionally more tension. That is the distinctive chime of capoed acoustic parts, and it is why a capoed G shape and a barred G at the 3rd fret sound different even though the pitches match.
The higher you go, the more pronounced it gets. Above the 7th fret the instrument starts to sound more like a mandolin than a guitar, which is sometimes exactly what an arrangement needs.
It is not cheating
This comes up a lot and it is worth being blunt: a capo is a transposing device, no more a shortcut than a horn player using a differently pitched instrument. Plenty of well-known acoustic recordings use one, precisely because the open-string sound cannot be obtained any other way. A basic spring clamp costs very little and will handle nearly everything you want to play.