Though musical modernism was a topic of frequent debate in the British press in the 1920s and 30s, until the 1990s, few scholars attempted to challenge underlying assumptions that modernism in British music was somehow less modern than the musical developments of its continental peers. This growing body of scholarship, however, has focused almost exclusively on male composers, ignoring the contributions of composers such as Elizabeth Maconchy (1907-1994), who was widely considered to be at the forefront of the younger generation of composers emerging during the interwar period.This dissertation examines Maconchy’s early career and its reception in conjunction with the political landscape of music in Britain during the interwar period. While the contemporary neglect of Maconchy’s music has often been attributed to gender discrimination, in the late 1920s and early 30s, Maconchy achieved renown despite the discouragement meted out by prejudice and incomprehension. By the late 1930s, however, the overall reception of Maconchy’s music began to shift. Her music, which had been welcome in the early part of decade and praised for its radically modern—yet at the same time distinctively “British”—idiom, came to be castigated by critics as the exact opposite by the end of the decade. This research contributes to a greater understanding of the intricate web of gender politics and shifting attitudes towards modern music in Britain by illuminating not only aspects of Maconchy’s early career that have been ignored and overlooked, but also the vital role played by nationalist ideologies in the decade leading up to the Second World War.