An ORATORIO is a type of religious musical work, usually composed of vocal solos, choruses, and instrumental pieces. It is typically based on a religious text, such as the Bible, and is often performed in a church or other religious setting. Oratorios are usually longer than operas and are often accompanied by an orchestra. They are often used to tell stories from the Bible or other religious texts, and can be used to celebrate religious holidays or commemorate important events.