A Frankie Valli concert these days starts with a film. It’s short, but it spans some 60 years of his singing career: “Big Girls Don’t Cry,” “Working My Way Back to You,” the Broadway jukebox hit “Jersey Boys.” A drum thumps, the band kicks in, and the man himself, 90 years old, emerges slowly from the wings of Boston’s Wang Theatre and launches into the 1978 song that was his seventh and (presumably) last No.
1 hit, the theme from “Grease.”.