What is the introduction to an opera called?
Sometimes it’s actually just called an introduction, more often an overture or a prelude. Wagner sometimes used the term “vorspiel.” The proper term is whatever the composer uses. Some operas, like Verdi’s “Otello,” start with an immediate curtain-raise and don’t have preludes at all. There are also some operas with preludes and introductions to later acts. Some of these are also called intermezzos or entr’actes. Most often, the music in these pieces is related to themes from the opera itself, but not always. Most of Rossini’s overtures have no thematic relation to the operas they begin. The one we hear beginning The Barber of Seville was actually used by Rossini for two other operas with no change to the music.
