Watch the Section 3: Twang online guitar lesson by Brad Carlton from Rhythmology

Harmonic Overview Chords: A7 D7
Street Key: A:I7 IV7
Theoretical Key: D: V G: V A Blues
Modes: A Mix D Mix
Parent: D Maj, G Maj - A Dor, G Maj
Pentatonic Options: A Min Pent, A Blues, A Maj Pent,
D Maj Pent