Looking at songs of 1917 that appeared in U. S. Billboard, songs showing awareness of the war seem common enough.

Over There- On Billboard 11 weeks, as sung by Nora Bayes.
Over There- On Billboard, 18 weeks, sung by American Quartet.
Over There, On Billboard 10 weeks, Peerless Quartet.
Till the Clouds Roll By- 10 weeks, Wheaton and Harrod.
Till the Clouds Roll By- 10 weeks, Prince's Orchestra,
Send Me Away With a Smile- 10 weeks, John McCormack
The Star-Spangled Banner- 8 weeks, John McCormack
Goodbye Broadway, Hello France- 8 weeks, American Quartet
Oh, Johnny- 9 weeks, American Quartet
Pack Up Your Troubles- 10 weeks, Knickerbocker Quartet.
La Marseilles- 2 weeks, Frances Alda
Someone Else May Be There While I'm Gone- 4 weeks, Al Jolson
Tramp, Tramp, Tramp, the Boys Are Marching- 4 weeks, Columbia Stellar Quartet.