The musical features a 1960s girl group reunited to revive some beach party fun. The core is solid 1960s with tunes like “Itsy Bitsy Teeny Weeny Yellow Polka Dot Bikini” and “It’s in His Kiss,” but it also dips further back with “Mambo Italiano” and rushes forward with 1970s feminist-tinged “I Will Survive” and “I’m Every Woman.” It opens Friday at the Westwego Performing Arts Theatre.