Definitions for "Oratorio"
A more or less dramatic text or poem, founded on some Scripture nerrative, 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.
Performance or rendering of such a composition.
A musical drama or narrative or operatic-like work, normally performed without costumes or scenery, with a Biblical text, composed for soloists and chorus (with alternating pieces such as arias, narrator, recitative, choruses, etc.), accompanied by instruments. [KRB, PAL