Dancers stretch. Musicians tune their instruments. Drag queens reapply lipstick. The familiar rhythm of Queen’s power anthem “We Will Rock You” blasts through the auditorium. And Nick Cannon arrives on stage in a pastel pink suit. Welcome to America’s Got Talent. “Audition 3” was full of energy, spotlighting gravity-defying tumblers, incredibly gifted children, and enough shirtless men to create an “AGT Pinterest board"