Thomas Arne

An overture is an orchestral piece that traditionally serves as the opening to an opera, ballet, or stage work, and later evolved into an independent concert genre. Two foundational models emerged in the Baroque era: the French overture (slow, majestic dotted-rhythm opening followed by a faster, often fugal section) associated with Jean-Baptiste Lully, and the Italian overture (sinfonia) with a fast–slow–fast three-part design that presaged the Classical symphony. During the 19th century, the overture expanded into programmatic concert works, sometimes called "concert overtures," that used sonata-allegro or hybrid forms to depict narratives, scenes, or dramatic ideas. Overtures are characterized by bold thematic statements, clear formal signposts, and striking orchestration for full ensemble—strings, woodwinds, brass, and timpani—often designed to set the dramatic tone, preview motifs, or energize an audience before the curtain rises.