There are three minor modes – Aeolian, Dorian, and Phrygian. Aeolian is the natural minor scale, so we will use this as our reference point (just like we used Ionian as a reference point for the Major modes). You can think of Aeolian two ways:
1 – Major scale with a b3, b6, and b7 (c-d-Eb-f-g-Ab–Bb)
2 – Major scale starting on the 6th scale degree (rewriting C Major CDEFGAB as A minor – ABCDEFG.)
We will use A minor as a reference. The Dorian mode is a minor scale with a #6 (A minor ABCDEFG becomes A Dorian ABCDEF#G). Another way to think of Dorian is the ii of a Major key. So, A Dorian is the ii in the G Major scale (GABCDEF# becomes ABCDEF#G).
The Phrygian scale is a minor scale with a b2 (A minor ABCDEFG becomes A Phrygian ABbCDEFG). Another way to think of Phrygian is the iii of a Major key. So, A Phrygian is the iii in the F Major scale (FGABbCDE becomes ABbCDEFG).
Play these scales until you can recognize them by ear.
Questions? Email nate@ultimateguitartraining.com