Watch the C Stars online guitar lesson by Brad Carlton from Chord Studies: Evolving Blues Vol. 2
This progression is a shuffle in C blues. On the second chord, E7, you'll notice that we derive the shape from a C7 open position folk chord. Also we are going to use a cross barre with the first finger to create an ascending line with the G♯. Moving to our typical Am shape your third finger will act as a pivot, and then glide down to grab the F9 chord.