MICHAEL WILLIAMS Neither Hendrix nor his heritage keeps this guitar hero from reaching beyond the blues     Michael Williams is well aware that he seems unusually cheery for a man who claims the blues as a birthright. “At first, I just wanted to be a guitar player,” he explains. “I never wanted to be a singer or a songwriter. But I found myself being pigeonholed and strictly defined as a blues player. That wasn’t intriguing to me. I wanted...