Though duty calls it's hard to say good bye /
Williams, W. R., 1867-1954, composer, lyricist.
notated music
eng
For voice and piano.
Popular music--United States--1911-1920.
World War, 1914-1918--Songs and music.
Also available in digital form on the Library of Congress Web site.
Performing Arts Encyclopedia
WWI sheet music
https://hdl.loc.gov/loc.music/2014564549