World War I Music
This is a great site if you are interested in the music of World War I. It provides a list of popular songs, as well as their lyrics and audio files if available.
More World War I Music
A smaller collection of World War I music, with their lyrics and audio files, is available here. In addition, the site has posted some vintage World War I posters.
And Still More About World War I Music
What sets this site apart is the lengthy overview of the music generated during the war. Songs are sorted into thematic and chronological groupings so that the full range of period music can be appreciated.
Eyewitness to World War I
Last but not least, this page compiles eyewitness accounts and provides brief overviews for the key moments during World War I.