MLA
Walters, B. Frank, and Ednor Rossitor. I Remember the Hour When Sadly We Parted. Lee & Walker, 1863. Stuart A. Rose Manuscript, Archives, and Rare Book Library, OP35, Folder 11. https://digital.library.emory.edu/purl/6214mw6nhb-cor.
APA, 6th edition
Walters, B. F., & Rossitor, E. (1863). I Remember the Hour When Sadly We Parted (OP35, Folder 11) [Sheet music]. Lee & Walker; Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/6214mw6nhb-cor.
Chicago
Walters, B. Frank, and Ednor Rossitor. “I Remember the Hour When Sadly We Parted.” Sheet music. Civil War Collection. Philadelphia, PA: Lee & Walker, 1863. OP35, Folder 11. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/6214mw6nhb-cor.