"out glides a soubrette from an operetta"

 

A soubrette is a secondary female character from an opera or operetta, usually sung by a soprano.  Examples include Susanna in 'The Marriage of Figaro', Zerlina in 'Don Giovanni' and Despina in 'Cosi fan tutte' (all by Mozart).  The character is often linked to the female lead in some way, perhaps as a confidante, and the singer's voice is generally lighter, to differentiate herself; for this reason, it is normally younger singers who take these roles.  Usually the character is portrayed as flirtacious, attractive and somewhat gossipy, and therefore tends to appear in comic works.  An exception is Belinda in Purcell's 'Dido and Aeneas', a tragic opera.

 Operettas are light operas.  Although still classically sung, they bear a close relation to musical theatre.  They developed during the 19th Century and were made especially popular by Offenbach.  Shorter and more comic than opera, some of the best known were produced in the later Victorian decades by the English Gilbert and Sullivan.  Still regularly performed, their best work includes 'The Mikado', 'H.M.S. Pinafore' and 'The Pirates of Penzance'.  These three productions all have soubrette characters of Pitti-Sing, Hebe and Edith, respectively.