One of my favorite songs our choir does at Christmas, is a "partner song" combining "What Child Is This?" and Scott Soper's "Child of the Poor."https://www.youtube.com/watch?v=IetPAANnhzQ
Another is "Silent Night" teamed with Daniel Kantor's "Night of Silence"https://www.youtube.com/watch?v=bcXfM-wc30c
Marty Haugen did a nice arrangement of "Night of Silence/Silent Night":https://www.youtube.com/watch?v=ANEk818VOqc