Watch the Already Barred online guitar lesson by Brad Carlton from Chord Studies: CAGED Chords Vol. 3
Our first chord here is derived out of the EDCAG system and is Am using the Gm form. To get the C chord using the A form, all you have to do is move your first and third fingers because your fourth finger will already be barring the third and second strings. Your third finger will be a guide as it comes down a fret and you shift into your D chord, using the C form out of the CAGED system.