I doubt if I've ever been to a Carol Service where we didn't have "O Little Town of Bethlehem". Sends a slight shiver down the back these days, mind you. (For some reason the fourth verse often gets left out - which I think is a shame, especially the last half of it.)

Another Carol which has the same poignancy in the context of the present situation in Manger Square is "Come, come, come to the manger", with its chorus ending "Stars of morning, o'er Bethlehem sing," and lines such as

The wintry wind blows cold and deary,
See, He weeps, the world is weary,
Lord, have pity and mercy on me.