An oratorio is a piece of music for orchestra, choir and solo singers. It usually tells a story from the Old Testament. An oratorio may be about two hours long: a whole concert. It is rather like an opera, but whereas an opera is acted out in costume on a stage, an oratorio is sung and played in a concert hall or church. The oratorio as we know it was created in the 18th century. The words were normally in the composer’s own language, not in Italian like most operas were at that time.