If they don't know the lyrics to "Lift Every Voice and Sing," then your choir should not sing "Go Tell It on the Mountain."

when the congregation gets to the fifth song about a "virgin's womb"

No one over the age of six should ever sing (the Kirkpatrick setting of) "Away in a Manger." Garbage song.

When someone brings up Carrie Underwood's version of "O Holy Night."