Question

A(n) _____ is an introductory section to an opera or oratorio.

Answer 1

The correct answer is overture.

Step-by-step explanation:

The overture is a form of composition of French origin and whose literal translation means openness. It consists of a piece, usually for orchestra, destined for its performance in concerts as an independent work, or to precede and prepare an opera, oratory, ballet, or some other play of a theatrical nature.

Answer 2

An overture is an introductory section to an opera or oratorio. It is an orchestral piece at the beginning of an opera, which gives introduction to the musical work.
The first significant use of a full-scale overture, however, was made by Jean-Baptiste Lully, in works such as his opera Thésée.