Capos are for cheaters, right?
Wrong! Yes, you can use a capo to make a song easier to play by allowing you to use more comfortable chords, or to raise or lower the vocal range of the melody. But what you’re actually doing is transposing: either actually changing the key of the song, or allowing you to play in one key while sounding in another. This lets you be much more flexible and versatile on guitar!
Do The Math
When we play a song, the chords have a specific relationship to each other based on the position of each chord’s root note in the scale. We can number the seven notes of the C major scale like this:
C=1 D=2 E=3 F=4 G=5 A=6 B=7
We number the chords the same way. So in the key of C, a C chord is 1, while a G chord is 5. The numbers work the same way no matter what key we’re in. Even more importantly, the relationships have a consistent sound no matter what key we’re in. We can really exploit the way this works on guitar by using a capo. Try this exercise:
Play an open position C chord, followed by a G, then back to C.
Place your capo on the 3rd fret and play A – E – A.
Move the capo up the the 5th fret and play G – D – G.
Move the capo to the 10th fret and play D – A – D.
You should notice that although the notes get higher, the chords sound very much the same. This is because the C and G chords can actually be played in different places all over the neck. The capo essentially makes the neck shorter and the pitch of each string higher. So when you play that A chord with the capo at the 3rd fret, the notes sound higher than they would be if you played it without the capo. The capo at the third fret raises the pitch of every note by three semitones or half-steps. So the notes you’re hearing are actually the notes of a C chord. We’re just using what we might call an A shape to reach them. The same applies to the next two examples.
If you do the math and count your way from A to E, G to D, and D to A, you’ll notice that you get the same number each time: 1 and 5. So what you’ve done is play a 1 – 5 – 1 progression in what looks like four different keys, but actually sounds in the same key each time.
It’s about the sound!
Now consider that if you learn more chord relationships and capo positions, you can play in every key in multiple places! Each capo position has a distinctive sound. In fact, the sound of some songs is defined by the use of the capo.
The Secret Formula!
Here’s a simple formula to help you find:where to put your capo to play a specific chord, or what chord is actually sounding.
There are three variables here, and if you know two you can find the third:
1. What fret is the capo on?
2. What chord shape are you playing?
3. What chord is actually sounding?
The formula works like this:
Chord shape + capo position = sounding chord.
In other words, take whatever fret the capo is on and count that number of steps up the chromatic scale (all twelve notes). This diagram will help:
Keep in mind that notes can be “spelled” as sharps or flats, which is why some notes have two names.
Let’s say you have a song in the key of F but you have trouble playing barre chords. Or maybe you just prefer the more ringing sound of the open chords. To find where to place the capo, start with the note F and count DOWN the chromatic scale to the nearest open chord name: A, C, D, E, or G. This will give you the fret number where the capo should go to make that chord shape sound as an F.
E shape = 1 half-step down from F = capo 1st fret
D shape = 3 half-steps down from F = capo 3rd fret
C shape = 5 half-steps down from F = capo 5th fret
A shape = 8 half-steps down from F = capo 8th fret
G shape = 10 half-steps down from F = capo 10th fret
Identifying the sounding chord
Conversely, let’s say you have a capo on the 3rd fret and you’re playing G, C, and D. To find what chords are actually sounding, count UP the chromatic scale three frets:
G shape + 3 half-steps = Bb
C shape + 3 half-steps = Eb
D shape + 3 half-steps = F
It will probably take some time before you really get to know the chromatic scale, but you’ll probably memorize the patterns you use most pretty quickly. After a while, you’ll be able to try out different capo positions to play the same song. If you’d like some reinforcement on the theory, check out this related post: A Crash Course in Capo Transposition.
And remember, sometimes we might choose a capo part because it sounds better, not just because it’s easier!