One name set the standard of cool for a generation. An Italian-American kid from the Bronx, Dion DiMucci skyrocketed to fame as a teenage heartthrob in the 1950s and early ’60s with hits like “Runaround Sue,” “Teenager in Love,” and “I Wonder Why.” Now, his extraordinary journey comes to the stage in a moving and intimate new musical about a life lived in the glow of the spotlight and in the shadow of addiction.