Watch the Phrygian online guitar lesson by TrueFire from Rock Guitar Greatest Hits Vol. 1
Lesson Source: Chris Buono's Modes That Matter
Sometimes it takes just one note to define a mode or a group of mode’s sound. Phrygian, the third mode of the diatonic series is a perfect example of this with its flatted 2nd degree. Check it out: 1 b2 b3 4 5 b6 b7. That b2 also is half of the defining tritone, which is set between b2 and 5. All in all, Phrygian has a borderline dark side, but a deceptively catchy feel, too.
Phrygian is so connected to that b2 it goes as far as almost negating the root based chord Phrygian produces, which is a minor triad or m7 tetrad. Both chords do not deliver the Phrygian vibe because the b2/b9 element is not present. This is the first example of a mode whose sound is best recognized by a progression or vamp. One that has a bII to i instance of some sort.
The following two segments will set Phrygian in a metal and Latin rock setting, both of which make use of progressions that exploit the bII.