Watch the Three Note Groups Pt. 4 online guitar lesson by Brad Carlton from Guitar Lab: Speed, Precision & Endurance Vol. 2
This lesson will deal with an augmented second interval which occurs in the Phrygian dominant mode. And augmented second is an interval encompassing a step and a half, which is three frets. The combination of a minor third followed by an augmented second occurs between the 1, b2, and 3 of the Phrygian dominant mode.