Watch the Familiar Territory online guitar lesson by Brad Carlton from Chord Studies: CAGED Chords Vol. 3
This progression is a ii - IV - V in the key of G, and we're using forms out of our CAGED and EDCAG systems. Here we're in open position, which is the position where our forms derive from. Although you may already be familiar with these chords, here's a technical tip: when moving from Am to C, don't pick up your first and second fingers. Instead let them act as pivot fingers. Make sure on your D chord you only hit strings one through four so the bass doesn't get muddied up.