Japanese Americans were involuntarily confined en masse during World War II. They were heavily scrutinized: their senses of belonging and identification were interrogated, contested, always fraught, and often ambiguous. During this tumultuous time, an American-born daughter of Japanese emigrants Ruth Watanabe (1916–2005), who would later become a notable and influential music librarian, head of the Sibley Music Library at the Eastman School of Music, corresponded extensively with a former teacher. In these letters, Watanabe provides an imaginative soundtrack for her daily life at the detention center at the Santa Anita Racetrack in California, while demonstrating ways that she drew on the European classical music tradition, in which she was highly trained, in order to maintain a sense of self and purpose amidst the confusion and indignity of mass confinement. This article briefly introduces some of Watanabe’s select activities at Santa Anita, contextualizing her work in the music department there against a backdrop of confusion and transience. The article includes large sections of text quoted directly from her letters in order to demonstrate that the sense of self and purpose expressed by Watanabe, and the resultant order and educational structures that she enacted in Santa Anita, can be understood to have been intrinsically aligned with her sense of belonging to her country—to “our country”—even as that very belonging was placed at risk by her involuntary confinement.