“For one reason or another, these more exaggerated and over-the-top sort of performances are coming out of me.”

At a truck stop somewhere outside of Boston, Marlon Williams holds a camera against the dashboard of his tour van and adjusts his headset to make room for his signature dangly earring. We’re talking about his upcoming appearance at San Francisco’s Hardly Strictly Bluegrass festival, and when I ask if he’s going to bust out some of his old bluegrass numbers, he agrees that the occasion is the perfect excuse…