How exciting and new the film Bob & Carol & Ted & Alice must have seemed when it hit pre-multiplex screens in 1969. Along with such contemporary classics as Midnight Cowboy and Easy Rider, and with the added inducement of major movie stars wearing few clothes, Paul Mazursky’s satire proffered trendy sex; inspired materialistic adults to question their values; laughed about pot, one of the first big releases to do so; spoofed middle-class mores; and served up newly permissible bare breasts, though not Natalie Wood’s or Dyan Cannon’s. As a time capsule, the movie holds up. But why, in 2020, do a musical version?