Free-to-use (ie public domain or copyright-free) means the words can be copied and sung to at least one tune with no concerns about copyright or performance licensing. Many such hymns are old/traditional - but where possible a variety of styles / genres are included.
Seasonal NoteMost communities have a familiar repertoire of public domain Christmas music, so at this time choosing free-to-use hymns is simple. The list below doesn't include all well known Christmas carols, just the ones that are a particularly good fit with the lectionary themes for this day and time.
ReadingsFirst: Isaiah- The Lord proclaims "Your saviour comes".
Psalm: Psalm 96 - This day new light will shine upon the earth, the Lord is born for us
Second: Titus - God's love was revealed out of compassion for us.
Gospel: Luke - The shepherds went to Bethlehem, and found Mary and Jesus in the manger.
Themes:Christ is born - the great light -Jesus our saviour
Hymn suggestions:Angels from the Realms of Glory
Angels we Have Heard on High
As with Gladness Men of Old
How Brightly Beams the Morning Star
Infant Holy Infant Lowly
Joy to the World
O Little Town of Bethlehem
Psalm 96 - Music for Mass setting
The First Nowell
The People that in Darkness Walked
Unto us a Child is Born
While by my Sheep I Watched at Night
While Shepherd Watched