He cited his ignorance of Sonny Boy Williamson’s blues back when Clapton was a member of the Yardbirds. Clapton says he thought every 12-bar blues was the same.

Edgar’s own proficiency at jazz also shines through with his attention to what makes jazz musically distinctive, from the structure of 12-bar blues to the parallels in form between ragtime and ...

There’s a lot of 12-bar blues tunes — ‘Johnny B. Good’ is a 12-bar format. It’s a certain pattern of chord progression that is standard.