''We weren't a social movement, like the Beatles,'' Bob Gaudio (Daniel Reichard) shrugs during Jersey Boys, a brisk musical about the original boy band, the Four Seasons. True enough, but their saga and songs finally give the jukebox musical a respectable name. With Frankie Valli vocal ringer John Lloyd Young and a book co-written by Woody Allen collaborator Marshall Brickman, Boys feels like an A&E Biography blended with a first-rate tribute band. The show overplays jokes about the combo's home state and swishy producer, but their crime-propelled rise-and-fall tale is so rarely told and oldies like ''Working My Way Back to You'' and ''Walk Like a Man'' are such minidramas in themselves that you leave feeling like you've heard pop's last great untold story. Not to mention humming ''Rag Doll.''