Opera comprises words, action, and music, but music is central. This book examines operatic music by five Italian composers—Rossini, Bellini, Mercadante, Donizetti, and Verdi—and one non-Italian, Meyerbeer, during the period from Rossini’s first international successes to Italian unification. Detailed analyses of form, rhythm, melody, and harmony reveal concepts of musical structure different from those usually discussed by music theorists, calling into question the notion of a common practice. An eclectic analytical approach is taken, using ideas originating in several centuries, from the sixteenth to the twenty-first. Music is analyzed at the level of the movement, the operatic number, the act, and the opera. Although no single theory accounts for all of the music examined, certain recurring principles define a distinctively Italian practice, one that left its mark on the German repertoire more familiar to music theorists.