More important was the prologue, consisting of sung dialogue between allegorical characters which introduced the overarching themes of the stories depicted.
[1] This French overture consists of a slow introduction in a marked "dotted rhythm" (i.e., exaggerated iambic, if the first chord is disregarded), followed by a lively movement in fugato style.
The overture is frequently followed by a series of dance tunes before the curtain rises,[5] and often returns following the Prologue to introduce the action proper.
In 19th-century opera the overture, Vorspiel, Einleitung, Introduction, or whatever else it may be called, is generally nothing more definite than that portion of the music which takes place before the curtain rises.
Richard Wagner's Vorspiel to Lohengrin is a short self-contained movement founded on the music of the Grail.
Other notable early concert overtures were written by Hector Berlioz (e.g., Les Francs juges (1826), and Le corsaire (1828)).
[1] The symphonic poem became the preferred form for the more "progressive" composers, such as César Franck, Camille Saint-Saëns, Richard Strauss, Alexander Scriabin, and Arnold Schoenberg, while more conservative composers like Anton Rubinstein, Pyotr Ilyich Tchaikovsky, Johannes Brahms, Robert Schumann and Arthur Sullivan remained faithful to the overture.
[1] In the age when the symphonic poem had already become popular, Brahms wrote his Academic Festival Overture, Op.
57 (1956), is a 20th-century parody of the late 19th century concert overture, scored for an enormous orchestra with organ, additional brass instruments, and obbligato parts for four rifles, three Hoover vacuum cleaners (two uprights in B♭, one horizontal with detachable sucker in C), and an electric floor polisher in E♭; it is dedicated "to President Hoover".
[13][14] In motion pictures, an overture is a piece of music setting the mood for the film before the opening credits start.