Oratorio (Lat. oratorium, a small chapel), a sacred musical composition, consisting of airs, recitatives, duets, trios, choruses, etc, with full orchestral accompaniment. The subject is generally taken from Scripture, and the text, which is seldom dramatic in form, is sung and recited without action or any of the adjuncts of theatrical representation. The oratorio is a modified form of the mystery or religious tragedy of the middle ages, adapted to the services of the church. Its origin has generally been ascribed to St. Philip Neri, who in 1564 founded the congregation of the Oratory in Rome, one of the objects of which was to deter young people from profane amusements by rendering religious services attractive. They began by the introduction of canticles and spiritual songs and choruses; and afterward Scripture songs and incidents were formed into dramatic poems, set to music by the best composers, and sung with instrumental accompaniment before and after the sermon. In the present signification of the term, however, oratorios were not produced until about the middle of the 17th century.
They speedily became popular in Italy, where they were regularly performed in churches during the carnival, and gradually became a recognized form of musical composition in many parts of Europe. In Germany they have been cultivated by eminent composers from Bach to Mendelssohn; and in England for a century and a half they have proved perhaps the most popular species of music extant. In the latter country all the great works of Handel, the most eminent composer of oratorios, including "Samson," "Israel in Egypt," "Saul," "Jephthah's Daughter," and the "Messiah," were originally produced. In some cities of the United States the taste for this kind of music has been fostered by societies of long standing. In Italy oratorios are performed exclusively in churches.