An oratorio is a large-scale dramatic composition using orchestra, chorus, and vocal soloists, normally on a sacred subject. Established in Rome in c. 1600 as a semi-dramatic treatment of a sacred subject performed in the oratory, but not called "oratorio" until 1640, this form has received attention from many distinguished composers, most notably Bach and Handel. The first oratorio was Emilio de Cavieri's La Rappresentazione dell' anima e del corpo ("The Representation of Soul and Body"), given in the oratory of the Church of Santa Maria in Vallicella, Rome, in 1600. The first German oratorio Historia der Auferstehung Jesu Christi (1623) by Heinrich Schütz. This work, however, is an adaptation of the Resurrection of about 1573 by Antonio Scandello.


In its earliest days oratorio was often accompanied by stage action, and even during the 19th century the more dramatic oratorios were sometimes presented as stage dramas. Perhaps the safest way to tell oratorio apart from opera is to decide whether a performance of a given work will be less effective without stage presentation. If so, the work is an opera. The definition is nevertheless vague, and it is because of this that it is impossible to state the identity of the most prolific composer of oratorios. If sacred works alone are considered, Handel's total is 18, and there are a dozen or so secular choral works. Antonio Draghi's total is 13 oratorios and 29 sepolcri, which were in effect staged oratorios.


The best known of all oratorios is Handel's Messiah. It is known and loved the world over by musicians and, inexplicably, by those with neither religious nor musical interest in the work and who would admit to listening to no other example of serious music. The reason for this may be the vast exposure given to the work, hardly a year passing without it being given at Christmas-time, and also often again at Easter, in most of the English-speaking musical centers of the world. This tradition took a few years to become established.


A performance in London's Westminster Abbey on 26 May 1784, held to commemorate the 25th anniversary of Handel's burial there, was planned on a mammoth scale: 95 violins, 26 violas, 21 cellos, 15 double basses, 26 oboes, 26 bassoons, 6 flutes, 12 trumpets, 4 sets of kettle drums, and, to enrich the lower line, a double bassoon, and specially-made 'double base (sic) kettle drums'. The chorus numbered 257 voices in addition to the soloists, and Joah Bates directed the performance from a harpsichord specially designed with levers connecting it to the organ, 19 feet (5.8 meters) away. The Royal Choral Society, established in London in 1873, celebrated its 230th performance of Messiah on Good Friday, 9 April 1982, so the tradition which lived through the Handel Festivals at the Crystal Palace annually from 1859 to 1926 (frequently with a choir of 4000) continues to the present day.


An unusual secular oratorio appeared in 1935. Its title is Wagadus Untergang durch die Eitelkeit (Wagadu Destroyed) by Vladimir Vogel, and it is scored for solo voices and chorus (sometimes using Sprechgesang, 'speech-singing') and just five saxophones.