Or`a*to"ri*o (?), n. [It., fr. L. oratorius belonging to praying. See Orator, and cf. Oratory.]
1. Mus.
A more or less dramatic text or poem, founded on some Scripture narrative, or great divine event, elaborately set to music, in recitative, arias, grand choruses, etc., to be sung with an orchestral accompaniment, but without action, scenery, or costume, although the oratorio grew out of the Mysteries and the Miracle and Passion plays, which were acted.
There are instances of secular and mythological subjects treated in the form of the oratorios, and called oratorios by their composers; as Haydn's "Seasons," Handel's "Semele," etc.
2.
Performance or rendering of such a composition.
© Webster 1913.