In 1973, a barely-out-of-his-teens Wilmington guitarist piled his gear into the drummer’s Chevy van to play their very first gig at a University of Delaware dorm. More than 4 decades, over 8,000 live shows, and some 15 million albums sold worldwide later, that same maverick guitar-slinger is still making electrifying music, still thrilling audiences, and still the most bad-to-the-bone performer in rock.