CHRIS SMITHER A veteran bluesman learns to make it happen all by himself    “People say to me, ‘What I really like is the fact that there’s a rueful cynicism in what you sing,’” says Chris Smither. “I can see that. But I have to say, in my own defense, that most of my stuff has an element of hopefulness. Usually I’m trying to point out there’s a way out of this stuff.” A veteran bluesman who looks on the bright side? Maybe—at...