The Village Carols publications have already been mentioned. One of my favourites, which has been sung at some of the festivals, but not this year, is an older translation of Adeste Fideles (Believers Assemble) with a more interesting tune (Portugal) than the well known one. So this is at the same time a close relation of the very well known O Come All Ye Faithful and yet very different.

And of course there are the umpteen alternative tunes for While Shepherds Watched.

Richard