One of my favourite songs is called Gaudete. It was probably composed in the 16th century, in celebration of Gaudete Sunday, the third Sunday in Advent. The earliest mention of this song is in a Swedish/Finnish book of songs, although the words are Latin. I like this version sung by the choir Libera, a group of boys from a church in North London.I remember singing this song at Christmas concerts in prep school. It's called Personent Hodie, another Latin song. I always loved the chorus, which went "Ide-o-o-o"... This song may have been written for the Feast of the Innocents, when King Herod had all the baby boys killed in hopes of eliminating the baby Jesus. I couldn't find a very good version of this song.
Another carol I love is called "Riu Riu Chiu", a Spanish song. Oddly enough, one of the versions I found on You Tube is by the 60's group, The Monkees! Riu Riu Chiu is the sound a nightingale makes and is the inspiration for this song.
On Christmas eve morning, as I have done for years, I will listen to the choristers at King's College Cambridge and their presentation of The Festival of Nine Lessons and Carols.It is my ambition to attend this in person one day.
Sorry for the bad formatting... it just wouldn't format the way I wanted it!