Watch the Using a Capo online guitar lesson by Susan Mazer from Hands On Guitar: Beyond Beginner
The capo raises the pitch of the guitar and, in turn, changes the key. When the capo is on the guitar and you’re playing a “G” chord, the guitar is no longer sounding a “G” chord. I’ll explain how the capo basically transposes the song. Now you can tell your bandmates exactly what key you’re playing in.