On the First Sunday in Advent, our congregation will sing (at the 10:30 Mass) a hymn that is not included in our Hymnal. “Savior of the nations, come” has a very interesting history, a genealogy which I explored in a recent audio program produced for Mars Hill Audio. You may listen to that program below. And you may download a pdf of the hymn here.
Part of that history involves a plainchant setting of an Advent hymn written by St. Ambrose (340–397). Our choir will be chanting that hymn during Communion in the 10:30 service tomorrow.
Here is the audio of the feature about “Savior of the nations, come” and its history.