The War Department (later renamed the Defense Department) in 1916 placed “song leaders” in the training camps for the military. Why?
“‘A songless army,’ says Major Gen. J. Franklin Bell, commander of Camp Upton, ‘would lack in the fighting spirit in proportion as it lacked responsiveness to music. There is no more potent force in developing unity in an army than in that of song.’”
We eventually won World War I, though it’s hard to say how much if anything song had to do with that. Still — from “cadence calls” that cadets sing out in time to their steps as they go on runs, to USO tours which bring popular music performers to entertain the troops overseas, music has always played a part in the U.S. military.
Teaching Uncle Sam’s Fighters to Sing: Organized Work Being Done Under Experienced Leaders in Camps All Over the Country — Difficulties of a Song Leader’s Job
From Sunday, September 30, 1917