Five years ago, dubstep was relatively unknown — reserved for hipsters and underground web chat rooms. Then “King of Dubstep” Skrillex kick-started the dubstep boom with “Scary Monsters and Nice...

Sunday concert-goers were greeted by electronic beats, rap, dubstep for Day Two of Boston Calling. Royal Teeth, a six-person band from New Orleans, kicked its performance off with “Hold Me” and...