The opera ballet (or ballet at entries ) is a lyric kind practiced in France at the 18th century, resulting from the Ballet from court.

More still than the lyric Tragedy of which many of its principles come, the opera ballet is a part of pure entertainment. It can be composed of a prolog, optional, and several acts (or entered ) of which intrigues, generally simplified to the extreme and based on the feelings in love, independent from/to each other but are connected by a common topic. A dominating place is left with the danced interludes whose pretext is provided by the action.

Heir to the Ballet of court, the opera ballet is distinguished from the lyric Tragédie by reducing to the maximum the action sung with the profit of the dance.

One of the first of the kind is composed by André Campra: gallant Europe (1697). The success of the formula causes many followers whose most famous Rameau with the gallant Indies is which content with the adventures in love in several “exotic” countries (Turkey, Perse, Empire INCA, North America) is at the same time one of its masterpieces and the most accomplished composition in this kind. The music in is sumptuous. But Rameau composes several others of them: Festivals of Hébé , Festivals of Polymnie , the Temple of Glory , Festivals of Hymen and the Love , Surprises of the Love .

the Louis de Cahusac, most faithful of the librettists of Branch, is one of the principal poets of the opera ballets of the 18th century, putting in scene contemporary characters, rather than the expensive heroes of mythology to the tragedy in music. Mixing comedy and imagination, diversity of the decorations and costumes (which change at each “entry”), the opera ballet is not less narrative and the dramatic action can, on the occasion, to take the form of true ballets - mimes.