What would “Eruption” sound like with a missing E string? How less epic would “For Whom the Bell Tolls” be with no pyro? The roadie is the unsung band member of rock, the man who makes the show all come together. He’s a guitar tech, light technician, drug dealer, and panty grabber all in one. The D pays tribute to this man of the shadows, and the thunderous orgasm of rock that he’s responsible for every time those Marshall amps blast at the rock show.