Answered
In Christianity
What is an oratorio?
"A musical composition for voices and orchestra, telling a sacred story without costumes, scenery, or dramatic action..
[Italian, after Oratorio , the Oratory of Saint Phili…p Neri at Rome, where famous musical services were held in the 16th century.]. From Answers.com.
It differs from opera in that there is no particular plot or interactions. It is often a piece of scripture set to music. .
Bach, Handel, and Haydn are just three composers noted for their oratorios. Handel's Messiah is probably the best known example. In this, various portions of scripture related to the promised Messiah, the events surrounding Jesus' birth, and the promise of his second coming are directly quoted and woven into a brilliantly cohesive and varied whole. Typically, oratorio is for any combination of orchestra, choir, soloist, and organ. All of these are used in the Messiah. . (MORE)