oratorio Definition

oratorio
noun oratorios

1. A musical composition, usually based on a Biblical or religious theme or story, sung by soloists and a chorus accompanied by an orchestra, but with no scenery, costumes or acting.
2. This type of musical composition or performance as a genre.

Etymology: 17c: Italian, from Latin oratorium oratory¹, so called because the form developed from the musical services held in the church of the Oratory of St Philip Neri in Rome.