My dissertation examines Protestant choral music in Korea from its introduction by American missionaries in the early 20th century through its transnational diffusion and development during the Cold War and after. Drawing on recent bodies of scholarship in postcolonial studies, Asian American Studies, and East Asian Studies, as well as a mixed approach involving ethnographic, critical, and historical methods, I argue that Korean Protestant choral music played an important role in mediating the experience of modernity in modern Korea and the Korean diaspora in the U.S. I explore the development of this music practice as a hegemonic cultural formation and contextualize its privileged position in the entanglement of secular and Christian musical conceptions of modernity and nationhood–an entanglement facilitated by Korean Protestantism’s close association with trans-Pacific modernity, with the U.S. at the center of this imagination. In addition to exploring the formation of normative choral and vocal music styles in historical context, I analyze the resistance of many practitioners to the demands and claims of cross-cultural musical syncretism and consider the controversial composition of neotraditional styles, which encode embodied, contested conceptions of Korean identity within a Western-style choral musical framework. This dissertation is a dynamic study of the ways in which colonial discourse concerning voice, nation, class, and gender shapes the affective and stylistic conditions of colonial and postcolonial music practices.