Scarlatti was an Italian composer of operas and religious works and one of the most important figures in the development of classical harmony. Scarlatti is noted for his thematic development and chromatic harmony, which he used with great mastery and in a way that anticipates the work of much later composers, among them W.A. Mozart and Franz Schubert. He is chiefly remembered for his operas, in which he established the form of the Italian overture (i.e., the opera overture in three sections, allegro-adagio-allegro), which was a forerunner of the classical symphony.

His chamber music is equally characteristic and shows him to havehad a commanding conception of form. More than 600 chamber cantatas from all periods of his life are extant. He wrote little orchestral music, but he contributed to the development of the opera orchestra. Whereas in his youth the strings were used mainly to play introductions and ritornelli (instrumental interludes), Scarlatti placed more emphasis on the orchestral accompaniment to the voices. His use of wind instruments was similarly novel: trumpets, flutes, oboes, and bassoons were used for particular effects, and horns were introduced into the orchestra.