Offertoire sur Deux Noëls by Alexandre Guilmant
This was one of my favorites pieces to play as a prelude for the fourth Sunday of Advent or Christmas Eve when I had a weekly church job.
The piece is interesting for me because it’s not obvious where it’s going. The very long introduction combines elements of both carols without committing to either one.
I wrote a blog post that talks about this and some other Guilmant pieces I love to play.