Watch the Modal Study #6 online guitar lesson by Jon Finn from Modal Rock Soloing
C Phrygian is an Ab major scale starting on its 3rd degree. C Phrygian is also a C major scale with b3 (Eb), b7 (Bb ) b6 (Ab) and b2 (Db). Another way to think of it is that C Phrygian is a C Aeolian scale with a b2. Further, C Phrygian is a C minor pentatonic scale (1, b3, 4, 5, b7 or C, Eb, F, G, Bb) with b2 (Db) and b6 (Ab) added. Since Phrygian is the only minor mode that contains b2, that note is considered the characteristic note.