obviously, and from reading I have done (Robert Graves, Siegfired Sassoon, et. al.) they were singing Christmas & New Years songs, Stille Nacht/SIlent Night, O Tannenbaum songs they could share in German and English, Auld Lang Syne, etc. The Music Hall songs listed above seem a bit too 'old' more common would have been Long Way to Tipperary, Mademoiselle from Armentières, etc. though they may be a bit later thatn 1914. THe Idea of adding the Belleau Wood song seems entirely out of keeping with the evening, unless it was added as a codao, or somehow introduced the events, I would stick to the songs that were actually sung, and there are many diaries, memoirs etc. that discuss the event and give titles. A little more research, I'll see what I can dig up.