In a sophisticated web of sound, the embodiment of masculinity and femininity in Italian opera underwent a substantive transformation during the first decades of the nineteenth century. What was deemed “masculine,” virile, and heroic made a marked shift away from the castrato-infused legacy of the eighteenth century. No longer were the castrati and their faithful proxy, the cross-dressed female travesti singers, seen and heard as acceptable leading “men” in opera. Instead, the Romanticism of Byron, Victor Hugo, Sir Walter Scott, and other emerging leaders in literature provided a new set of topics for plots and heroic situations. The classical symmetry and rational aesthetics of the Enlightenment gave way to a new form of realism that relied on the power of genius now fueled by the subjectivity of emotion. In the period following the French Revolution the idealized power of the monarchy was replaced with the articulation of strength and courage through individual acts of bravery. Within this world, the Romantic male protagonist also redefined heroism vocally. As a tenor, he sang with a differently articulated virtuosity from that of the castrato bel canto aesthetics and he offered the sound of an unaltered and unmistakably male voice.

As the conventions surrounding masculinity and femininity in opera were realigned to the principles of Romanticism, the typical operatic roles for male and female singers changed. Across the two halves of the nineteenth century, women's roles in opera underwent a substantive change.