Nicknamed by his contemporaries "the Italian Orpheus", he divided his career between Naples and Rome, where he received his training; a significant part of his works was composed for the papal city.

Particularly known for his operas, he brought the Italian dramatic tradition to its maximum development, begun by Monteverdi at the beginning of 17th century and continued by Cesti, Cavalli, Carissimi, Legrenzi and Stradella, designing the final form of the Da capo aria, imitated throughout Europe.

Scarlatti's style, however, is more than a transitional element in Western music; like most of his Naples colleagues he shows an almost modern understanding of the psychology of modulation and also frequently makes use of the ever-changing phrase lengths so typical of the Napoli school.

His early operas—Gli equivoci nel sembiante 1679; L'honestà negli amori 1680, containing the famous aria "Già il sole dal Gange"; Il Pompeo 1683, containing the well-known airs "O cessate di piagarmi" and "Toglietemi la vita ancor," and others down to about 1685—retain the older cadences in their recitatives, and a considerable variety of neatly constructed forms in their charming little arias, accompanied sometimes by the string quartet, treated with careful elaboration, sometimes with the continuo alone.

His best operas of this period are La Rosaura (1690, printed by the Gesellschaft für Musikforschung), and Pirro e Demetrio (1694), in which occur the arias "Le Violette", and "Ben ti sta, traditor".

From about 1697 onwards (La caduta del Decemviri), influenced partly perhaps by the style of Giovanni Bononcini and probably more by the taste of the viceregal court, his opera arias become more conventional and commonplace in rhythm, while his scoring is hasty and crude, yet not without brilliance (L'Eraclea, 1700), the oboes and trumpets being frequently used, and the violins often playing in unison.

These represent the most intellectual type of chamber-music of their period, and it is to be regretted that they have remained almost entirely in manuscript, since a careful study of them is indispensable to anyone who wishes to form an adequate idea of Scarlatti's development.