An oratorio is a large-scale musical composition for orchestra, choir, and soloists. It typically features sacred text set to music, and it is usually performed in a concert setting rather than on stage with acting and staging like an opera. Unlike operas, oratorios do not generally include costumes or scenery.
To clarify the other terms you mentioned:
- A madrigal is a type of secular vocal music composition that originated during the Renaissance, often featuring intricate polyphony.
- An aria is a solo vocal piece that is part of an opera, characterized by expressive melodies and is often used to convey a character's emotions.
- An elaborate stage show would generally refer to a theatrical production, which can include operas but is not synonymous with oratorios.
So, among the options you provided, "sacred text set to music" is the most accurate definition of an oratorio.