Imagine being in a war zone trench, just feet away from the enemy’s on Christmas Eve. Such a thing occurred on December 24, 1914 when carols were sung between the British and German soldiers. Perhaps it sounded something like this: O Tannenbaum, o Tannenbaum, Wie treu[N 1] sind deine Blätter! Du grünst nicht nur zur Sommerzeit, Nein, auch im Winter, …