"Perfect Young Ladies" is the opening number - after the overture - from the 1954 Sandy Wilson musical The Boy Friend
(spelt thus). Running to around a minute and a quarter, it is performed by Dulcie, Fay, Hortense, Maisie, Nancy and ensemble.
The first performance was actually a try out at the Player's Theatre Club on April 14, 1953, but it did not open in the West End until January 14 the following year. Julie Andrews starred in the original Broadway production which opened at the Royale Theatre (English spelling), on September 30, 1954, and in 2003, nearly half a century later, she made her directorial debut with the same show. In 1971, a film version starred Twiggy in the lead role; this version included additional songs, including, curiously, "Any Old Iron