This song is a Gaelic version of the Christmas carol "Silent Night."
Enya released this song for the first time back in 1988, originally as a b-side of the "Evening Falls" single. This is a re-recorded version. Enya commented on her website: "It was exciting to re-live 'Silent Night.' It is re-released every year in America and it was so nice to go back and do something different with it."
The new rendering incorporates multi-layering Enya vocals. Enya commented: "I enjoy the process, I love the excitement of not knowing if it will work."