This dissertation traces the emergence in late eighteenth-century Italy of an ideological connection between voice and subjectivity, arguing that this link was forged as a means of assuaging anxieties about Italy’s role in European culture. For most of the century, virtuosic voices had dominated Italian “serious” opera: onstage, singers flaunted flashy embellishments while projecting the static categories of the Cartesian passions. But after midcentury, as new epistemologies of emotion converged with neoclassical aesthetics, Italian musicians and literati increasingly criticized those voices as inauthentic and unfeeling. In order to redeem voice, and with it Italian culture, reform-minded singers and intellectuals rebranded Italy’s most famous export as an agent of moral edification. They asserted that voice could make audible the interiority of a feeling subject, and potentially represent the political agency of that subject. Some reformers even attributed to certain voices the power to civilize humanity by cultivating feeling, inspired by the myth of Orpheus’s lyric song. The resulting complex of discourses and practices is what the dissertation calls “the lyric mode of voice,” a phrase which combines the ancient generic definition of lyric as musical poetry with the late-eighteenth-century literary mode characterized by emotional intensity, vivid subjectivity, and expressive immediacy. The dissertation explores the lyric mode of voice through representations of two archetypal poet-singers, or lyric figures: Orpheus and Sappho, who functioned both onstage and in literature as dynamic symbols of “authentic,” subjective vocal expression. By articulating the ways in which the lyric voice was rendered as cultural and political power, this dissertation unpacks still-resonant myths about uniqueness and agency. It does so by interweaving historically-situated musical analysis with interpretive threads from literary theory and philosophy. It thus intervenes in musicology by placing historical musical-vocal practices into dialogue with intellectual history, and contributes to Italian studies, eighteenth-century studies, and the history of ideas by demonstrating how intellectual histories might be excavated from the residues of sonic practices. In approaching voice as both a discursive category and a set of culturally contingent practices, the dissertation ultimately considers how historical ideologies and practices of voice together inflected “modern” constructions of subjectivity.