Progression
The Blues turnaround in E major
Blues turnaround in E major plays E, C#7, F#m7 and B7 — I, VI, ii and V — across 4 chords. I–VI7–ii7–V7, the four-bar turnaround that closes a blues chorus and sets up the next one.
The chords, in order
1EI
2C#7VI
3F#m7ii
4B7V