The document summarizes the Classic Era of opera from 1750-1820. It describes the characteristics of early classic Italian opera, including small casts consisting of castrati, sopranos, tenors, and the structure of da capo arias and ensembles. Intermezzi were short comic operas performed between acts of serious operas. Opera buffa were full length comic operas influenced by commedia dell'arte. Italian opera was popular throughout Europe, with composers like Hasse, Pergolesi, Jomelli, J.C. Bach, and Traetta producing operas in Italy, Germany, and Russia. Christoph Willibald Gluck's operas emphasized dramatic unity and simplicity to heighten