In the years that immediately followed the Armistice of November 11, 1918, Paris was at a turning point in its history: the aftermath of the Great War overlapped with the early stages of what is commonly perceived as a decade of rejuvenation. This transitional period was marked by tension between the preservation (and reconstruction) of a certain prewar heritage and the negation of that heritage through a series of social and cultural innovations. In this dissertation, I examine the intricate role that nostalgia played across various conflicting experiences of sound and music in the cultural institutions and popular media of the city of Paris during that transition to peace, around 1919-1920. I show how artists understood nostalgia as an affective concept and how they employed it as a creative resource that served multiple personal, social, cultural, and national functions. Rather than using the term “nostalgia” as a mere diagnosis of temporal longing, I revert to the capricious definitions of the early twentieth century in order to propose a notion of nostalgia as a set of interconnected forms of longing. Drawing from journalistic and archival sources, histories and theories of nostalgia, and musical and cultural studies of Paris, I interrogate the continuities and discontinuities among the political, economic, and social forces affecting musical nostalgia in the aftermath of a costly, global war. I show that nostalgia was a complex notion engaging a multiplicity of meanings and functions that were experienced and cultivated collectively in a variety of musical activities in the public sphere. Nostalgia not only expressed resistance to change, but also conveyed progress and offered answers to collective debates about postwar memorialization, French national identity, and cultural modernism. The music that I discuss, ranging from concert favorites to unpublished songs, demonstrates that genres and venues usually studied separately were informed by similar struggles in defining their continuing relevance in a new era. This music also sheds light on the interconnectedness of apparently distinct markets for nostalgia and how they intersected with civic life, politics, urbanism and nationalism.