Historia de la Música Boliviana (History of Bolivian Music) was published by composer, violinist, and musicologist Atiliano Auza León in 1985, detailing the music and musicians of the country in what was considered the first Bolivian musical history of its kind. In this paper, I bring Auza León’s Historia de la Música Boliviana to an English-speaking audience for the first time, critically engaging with his portrayal of Indigenous music in the context of 20th century mestizaje and Indigenismo among Bolivian composers and institutions. By interrogating his position in the creation of musical authority and cultural development in Bolivia at the time, I engage with Auza León’s stature as a national composer. I explore the state’s sponsorship of his music and scholarship while situating his productions within Bolivia’s political and musical consciousness of mestizaje, or racial mixing. Then, I analyze a key chapter from his Historia de la Música Boliviana, placing his text within this trajectory. Auza León’s epistemolization as a musical authority occurs as a result of the mestizo perspectives taken in his compositions and writing, constructing an identity around Bolivian music predicated on mestizaje.