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Operetta (It., diminutive of 'opera'; Fr. opérette; Ger. Operette; Sp. opereta). A light opera with spoken dialogue, songs and dances. The form flourished in Europe and the USA during the second half of the 19th century and the early part of the 20th. In the 17th and 18th centuries the term 'operetta' was applied in a more general way to a variety of stage works which were shorter or otherwise less ambitious than opera, such as vaudeville, Singspiel and ballad opera. It is still in use on the Continent for new works akin to the Musical Comedy, into which the operetta evolved in English-speaking countries.

The policy of the Théâtre de l'Opéra-Comique to favour works of more serious pretensions left a gap between opéra comique and vaudeville, a gap that the operetta filled. The success and popular acclaim accorded Offenbach's opéras bouffes, an individual new form of entertainment, led the operetta to become established as a separate genre, and the resultant attempts to emulate Offenbach's success abroad brought into being other national schools of operetta and established the genre internationally.

"Taken from The New Grove Dictionary of Music and Musicians"

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