How did Alessandro Scarlatti influence Neapolitan opera?

Alessandro Scarlatti was a pivotal figure in the development of Neapolitan opera, helping Naples rival Venice as a center for the art form by the year 1700. His influence was primarily exerted through his prolific output of over 30 operas written for the Teatro San Bartolomeo between 1684 and 1702.1

His key contributions include:

• Development of the Da Capo Aria: Scarlatti is central to the refinement of the da capo aria, a large-scale ABA form that became a hallmark of Neapolitan opere serie. He used these arias to create musical portraits of a character's state of mind, imbuing them with unusual depth and rich instrumentation.21
• Orchestral Innovation: He contributed significantly to the development of the opera orchestra. Moving beyond the use of strings for simple introductions, he emphasized orchestral accompaniment to the voices and introduced wind instruments—such as trumpets, flutes, oboes, bassoons, and horns—for specific dramatic effects.2
• Structural Formalization: Scarlatti established the form of the Italian overture—a three-section structure (allegro-adagio-allegro)—which served as a vital forerunner to the classical symphony.2