Clive Donner's "Here We Go Round the Mulberry Bush" makes it abundantly clear that the mad, stylish, with-it new British comedies are the true heirs of the beach-party boom. Do not ask what became of Frankie Avalon; look around ye.
Both the beach-party movies and the swinging London movies have their roots in the Hollywood musicals of the Depression. The idea then (as now) was to sell music, fashions and sex, seem to be terrifically modern and ignore the problems of the real world. In the universe of Fred Astaire and Ginger Rogers, there was no hunger or despair.
That was also the idea of the beach parties (none of which, as I recall, were integrated). The new British movies like "Mulberry Bush," "Smashing Time" and "To Sir, with Love" aren't so naive. They deal with controversial issues, although not from a controversial point of view. You are likely to see Prime Minister Harold Wilson in his bathing trunks, for example, but Sidney Poitier still doesn't get the girl.
The approach to sex is likewise traditional. In the 1960s as in the 1930s, there is a lot of smooching, but the girl still stays out of bed. In the old days it was her virtue that kept her unspoiled; now it is her ennui.