For the ninth day of Christmas, here’s Nova Nova Ave Fit ex Eva by Williametta Spencer. This one also works for the Annunciation, being based on Luke 1:26-38.
There appears to be sheet music available at J W Pepper.
Christmas is very nearly upon us, but Sunday morning is still Advent.
2 Samuel: King David lives in a house of cedar but the Ark of God dwells in a tent; David finds this disconcerting but God seems to have very particular ideas about it, and makes a covenant with David.
Psalm 89, or bits of it: very much about God’s anointed and the covenant with David. But you could use the Magnificat instead here.
Romans: So many ideas touched upon in only one sentence! Strength and faith in Christ; mystery and prophecy and wisdom. But the main idea is to give glory to God.
Luke: The Annunciation. An angel appears to Mary and tells her she’s going to get pregnant despite being a virgin.
The obvious choice of music here is Mary’s Whys by Helen Williams. There’s a recording online and you can download the score for free from Canossa Choral Music. Sarah Lutton’s poem imagines Mary’s response to being asked to bear the Son of God.