St. Olaf's Castle in the context of Medieval

Opera is a form of Western theatre in which music is a fundamental component and dramatic roles are taken by singers. Such a "work" (the literal translation of the Italian word "opera") is typically a collaboration between a composer and a librettist and incorporates a number of the performing arts, such as acting, scenery, costume, and sometimes dance or ballet. The performance is typically given in an opera house, accompanied by an orchestra or smaller musical ensemble, which since the early 19th century has been led by a conductor. Although musical theatre is closely related to opera, the two are considered to be distinct from one another.

Opera is a key part of Western classical music, and Italian tradition in particular. Originally understood as an entirely sung piece, in contrast to a play with songs, opera has come to include numerous genres, including some that include spoken dialogue such as Singspiel and Opéra comique. In traditional number opera, singers employ two styles of singing: recitative, a speech-inflected style, and self-contained arias. The 19th century saw the rise of the continuous music drama.

Castle chapels (German: Burgkapellen) in European architecture are chapels that were built within a castle. They fulfilled the religious requirements of the castle lord and his retinue, while also sometimes serving as a burial site. Because the construction of such church edifices was expensive for the lord of the castle, separate chapels are not found at every seat of the nobility. Often, a secondary room furnished with an altar had to suffice.

According to historian Sarah Speight, "The religious role of chapels was as normal, as routine, and arguably, as integral to castles as any concern for symbolism and/or military strength."