Christmas Carols: Verbum Caro Factum Est
The refrain of this carol, "Verbum caro factum est" comes from John 1:14 ("And the word was made flesh"). The rest of the song consists of the virgin Mary telling Jesus that she would do anything for him, but she has nothing to give him.
Here are three 15th century arrangements of the hymn:
Chanticleer, Francisco Guerrero arrangement:
Notre Dame Choir, New York City, 2008, Orlande de Lassus arrangement:
South Dakota Honor's Choir, 2007, Hans Leo Hassler arrangement:
Unfortunately the very first part of this song is cut off, but it's still my favorite version.
Honorable Mention: The Sixteen, singing an arrangement by John Sheppard.