A classic Blues shuffle, many people relate to this progression as a song called, “Key To The Highway”, covered by Eric Clapton amongst others.

Played on a slightly distorted acoustic, this eTrax is ideal for mastering your Blues licks and is equally suited to clean and subtle soloing or a screaming distorted style.

The bass is playing major riffs, so the major pentatonic works well (Think BB King), although as with most Blues pieces – you can get away with the minor pentatonic and blues scale.
The Mixolydian mode works particularly well. Try A mixolydian over the A, A dorian over the D and A major over the E.