1. The ending is different:

The two themes here remain on the same main key, and the second theme does not change the key. Sometimes a coda is used after the recapitulation to end the whole piece. This coda is mostly composed of the original theme, but sometimes new musical materials can also be quoted;

For example, Beethoven's "Egmont" The overture ends with the new victory march. Also, sometimes you can add an introduction before the presentation.

2. Different forms:

An opera overture must maintain an organic connection with the opera itself. The easiest way is to directly excerpt the fragments or the most closely related to the plot development in the opera. A melody (such as an aria, etc.) that can reflect the character of the opera protagonist is used as the theme. The overture to Mozart's opera "Don Giovanni" and the overture to Glinka's opera "Ruslan and Lyudmila" are examples of this aspect.

However, some overtures have no thematic connection with the opera itself, such as the overture to Mozart's opera "The Marriage of Figaro" and the overture to Rossini's opera "The Barber of Seville".

3. Different genres:

The former has no specific plot, while the latter is related to the plot. The overture is one of the oldest instrumental music genres and played an important role in the development of other instrumental music genres, especially symphonies and symphonic poems. As the name suggests, an overture can be compared to the preface or introduction of a work. In music, it originally refers to a prelude-style instrumental piece before the performance of an opera, oratorio, cantata, dance drama or other dramatic work, which is mainly a slapstick piece. music.

The early stage music was very simple. It was actually just a few loud horn blasts, which is equivalent to three bells before a theater performance today. This was the case in ancient folk fair stages or puppet shows, and by the beginning of the 17th century it was sometimes still the case in Italian operas, such as Monteverdi's operas.