Watch the G Form: Double Stop Exercise online guitar lesson by Dave Celentano from CAGED Commander

The only note in this exercise that's outside the 'G form' scale pattern is the 9th fret/G string which is relocated from the 5th fret/B string to accomodate the double stops in bar 2. Expanding beyond the scale form at hand gradually helps you see how the five scale patterns in the 'CAGED' system connect.