This chapter considers constructions of the Argentine operatic canon in the years immediately preceding the First World War, focusing on Mascagni’s Isabeau. Premiered at Buenos Aires’s Teatro Coliseo in June 1911, the reception of Isabeau outlined competing efforts by critics and managements to shape a specifically Italian-Argentine operatic canon: one that could stand in for local compositions while moving away from the conventions of Cavalleria and Pagliacci. These ambitions were also shaped by concerns over the integration of Italian immigrants, in spite of the enduring success of many Italian operas and critical scepticism that surrounded more recent premieres of Wagner and Strauss. From an Italian perspective, meanwhile, Isabeau’s foreign profile intersected with broader questions of citizenship, nationhood and affective belonging that played out within both political and musicological discussions during a period when dual citizenship was legally impossible. Ultimately, the nationalist drives at work during the 1910s influenced the operatic canons we still draw on today, I argue, affecting critical attitudes towards non-Italian and emigrant composers alike.