Short answers, pulled from the story.
Italian composers began writing these orchestral pieces in the late 1600s. These short introductions replaced earlier prologues and set the stage for the drama that followed.
The typical piece features three distinct sections arranged by tempo with a quick-slow-fast pattern. The first movement moves quickly, the second section slows down significantly, and the final movement returns to a fast pace similar to the opening.
Alessandro Scarlatti stands as the central figure behind the form's popularity during its rise. His compositions demonstrated how the structure could support dramatic storytelling without words.
During the early 1700s musicians referred to these pieces primarily as sinfonie rather than overture because the word described any orchestral introduction regardless of national origin. Critics and publishers began using Italian overture more frequently to distinguish this specific type from others.
Composers around 1750 adapted the quick-slow-fast pattern into larger works that defined the classical era. This evolution transformed simple theater music into complex standalone pieces performed in concert halls.