I'll apologize first. I don't know how to post the actual You Tube videos so will only post the links.
The first is Gesu Bambino sung by Jesse Norman. Her voice is really to big for this type of song but as usual her technique and beautiful full voice are awesome.
The second is Marie Wiegendlied (Mary's Lullaby) by Sissel Kyrkjebo. I'm not familiar with her but she treats the carol with the tenderness it needs.
They are both quite and gentle. A nice come down from all the racket of commercial Christmas.
So tip toe past the sleeping kittens.