The legacy of Stevie Ray Vaughan is not in his guitar playing. It’s in his heart. The blues was not born with the Texan guitarist, but it was given a second life. Twenty-five years after his death at age 35 in a freak helicopter crash, many still find the blues synonymous with Vaughan’s name. Many also mistakenly think it died with him in that helicopter on Aug. 27, 1990. Somehow during the quarter-century since Vaughan’s tragic passing, “blues” has become a bit of a dirty word. Make no mistake, there are still blues players among us: Jack White, Dan Auerbach...