noun, plural or·a·to·ri·os.
- an extended musical composition with a text more or less dramatic in character and usually based upon a religious theme, for solo voices, chorus, and orchestra, and performed without action, costume, or scenery.
noun plural -rios
- a dramatic but unstaged musical composition for soloists, chorus, and orchestra, based on a religious theme
n.“long musical composition, usually with a text based on Scripture,” 1727 (in English from 1640s in native form oratory), from Italian oratorio (late 16c.), from Church Latin oratorium (see oratory (n.2)), in reference to musical services in the church of the Oratory of St. Philip Neri in Rome, where old mystery plays were adapted to religious services. A musical composition for voices and orchestra, telling a religious story.