abstract: It is no secret that the Soviet Union silenced the voices of many artists, but pieces of this history are still emerging—including the story of Ukraine's first female composer to achieve professional renown: Stefania Turkevych (1898-1977). Although the quantity and quality of Turkevych's compositional output should have established her as a major international figure, most of her work remains unpublished. Turkevych is absent from both Grove Music and Die Musik in Geschichte und Gegenwart (MGG Online). There is a clear need for English-language biographical materials about Turkevych and for publication of her works. This document represents the first critical edition of Turkevych’s three-act chamber opera, Серце Оксани (The Heart of Oksana), commissioned in 1969 for the 100th anniversary of the creation of Canada’s Province of Manitoba (and its subsequent settlement by members of the Ukrainian diasporic community). The score is prefaced by brief introductions to both Turkevych and Серце Оксани as well as an explanation of editorial procedure and a critical report. Lost Soviet-era voices carry particular social and political weight as present-day Ukraine reclaims an identity that moves beyond reductive “Russian vs. European” dichotomies, and solidifying that identity seems even more urgent against the backdrop of the current Donbass War (2013-present). This project represents the first step in a much longer-term effort to unearth and share Turkevych’s story and overlooked contributions as a composer, teacher, and lifelong advocate of Ukraine’s language and culture. / Dissertation/Thesis / Doctoral Dissertation Music 2020