An '''oratorio''' is a large musical composition for orchestra, choir, and soloists, according to Wiki/TheOtherWiki. Like an opera, an oratorio has recognizable characters, and is similar in length. Oratorios also tell a story, with particular singers assigned the roles of certain characters (usually, the soloists get the lead parts and the choir plays the role of GreekChorus). But unlike operas, oratorios are strictly concert pieces, with no props or costumes.

Oratorios are usually religious in nature, telling a story from the Bible or a saint's legend. The form was invented to keep the opera singers employed during Lent, when the theatres were closed down.

Oratorios are also similar to [[{{Cantata}} cantatas]], in that cantatas are also large-scale vocal works and occasionally identifiable characters, but they usually do not tell a story (Bach's [[Music/SchweigtStillePlaudertNicht Coffee Cantata]] is a notable exception).

The generally recognized king of oratorios is Music/GeorgeFredericHandel (much as his contemporary UsefulNotes/JohannSebastianBach was the king of cantatas), who wrote lots of them because they were cheaper to produce than operas but brought in nearly as many people . Handel's ''Messiah'' (the source of the famous Hallelujah chorus) is probably the best-known oratorio out there, though J.S. Bach's two extant oratorios, the St. Matthew Passion and the St. John Passion, are also well-known.