An oratorio is a musical composition for voices and musical instruments which is usually sacred in nature. Oratorios are typically inspired by religious stories, although they usually include text written specifically for the oratorio, rather than text from the Bible or another religious book. The most noted composer of oratorios is probably George Frederic Handel, who wrote The Messiah, one of the most well-known oratorios in the world.
This musical style developed in the 1600s, and the composition of oratorios continues to this day. Initially, oratorios were purely religious in nature, and in fact they arose from an older tradition of religious music designed as a form of entertainment to draw in converts and lapsing churchgoers. Modern oratorios are sometimes more secular in nature, although most involve serious themes, even if they do not touch upon religious issues.
Many people compare oratorio to opera. After all, both forms feature an orchestra and singers. However, there are a few key differences which can be used to distinguish an oratorio from an opera. The first is the lack of costumes, props, staging, and action in an oratorio. Singers typically remain seated on stage along with the orchestra, rising when they need to perform or remaining seated, depending on regional tradition. Oratorios are also very heavy on the chorus, using the chorus for emotional moments where the orchestra would normally appear in an opera.
A typical oratorio opens with an overture performed by the orchestra alone. The overture establishes the basic themes of the piece, laying the groundwork for the composition as it unfolds. Individual singers may sing arias to propel the story, and the use of recitative is also typically heavy in an oratorio. Oratorios also feature, as discussed above, a lot of choral work, and many are extremely long. The finish of the oratorio often includes a reprise of the major musical themes performed by the orchestra so that the audience knows the work is drawing to a close.
Oratorios tend to be especially popular around the holiday season. Most residents of urban areas can find an oratorio to listen to in December, often The Messiah, in fact. Oratorios are also performed sporadically throughout the year by various orchestras and religious organizations. Many groups perform abridged versions of the oratorio, since many noted compositions can last for five or six hours, too long for most modern audiences.