from Dave Rubin's Inside the Blues
A diagram of the basic blues box from which T-Bone played almost exclusively for his entire career is shown below. This box, as well as its other four forms, are moveable to all keys. In the key of A, the notes are A, C, D, Eb, E, and G (formula: R–b3–4–b5–5–b7).
T-Bone would also alter the basic blues scale with notes from the Mixolydian mode. The notes in the A Mixolydian mode are A, B, C#, D, E, F#, and G (formula: R–2–3–4–5–6–b7).
When you combine the two, a hybrid blues/Mixolydian mode scale results.
T-Bone’s artistry was in his skillful manipulation of these notes into carefully structured blues phrases, not in mindlessly running up and down the scales. Rigorous investigation reveals fluid, swinging triplets throughout his solos and fills. The audio track is a vocabulary of T-Bone-type blues licks, one bar in length, and broken down into which chord change they most likely would be played over. Be aware that many licks can be played over the other two changes, as well. Listening and analyzing T-Bone’s actual recordings will be your best guide.
T-Bone's Favorite Phrases