According to Dennis Bratcher at The Voice we can begin singing Christmas carols on the Third Sunday of Advent, the Sunday of Joy.
It is important, in terms of the purpose of Christian Holy Days as teaching tools of the Faith, that Advent and Christmas be different, with different emphases, especially on the first two Sundays of Advent. These need to emphasize expectation and longing, a preparation for celebration much as Lent is a preparation for Easter. Without that, the season becomes one long celebration without any context for that celebration and with little contact with the reality of life that gave birth to the season in the first place.Of course there is a progression to the services of Advent. By the third Sunday, which is usually the Sunday of Proclamation with the Magi or the Shepherds, or the Sunday of Joy, we can begin celebrating, not because it is all finished but because the promise is moving to reality, because we have heard from God and have the promise in concrete terms. It is in that movement from distant longing and crying out on the first Sunday, to hope and immediate expectation on the Second, to Joy and proclamation on the Third Sunday, that prepares us for praise and celebration on the Fourth Sunday as the year moves into the Christmas Season. If done well, that liturgical movement takes people along in the journey of their lives, as they enact their own experiences in worship. It gives people a structure in which to take the vagueness of their own distant longings as they identify with Israel’s longings, and brings them to an expressed hope and faith that God is, indeed, "with us." It is this journey that gives people a context for celebration.
We will be singing "Joy to the World" this Sunday, which was not originally intended as a Christmas carol, but rather a song about the return of Christ, based on Psalm 98, although it definitely works as a Christmas song (we'll be slapping some sleigh bells on it). It actually works better as an Advent song, if you think about it, with its great theme of the Second Coming of Christ.
Unfortunately, like many Christmas carols, we have sentimentalized this tremendously rich song, which is packed with deep kingdom and eschatological proclamations. Have you ever gone beyond the sentimentality of "Joy to the World" to reflect upon its theology? If you have, one of the first things you noticed is the (seeming) grammatical bourde in the first line: "the Lord is come." Many change the word "is" to "has," so that it makes more sense as a Christmas song. Wikipedia notes:
In the first line of the first verse, we might expect to hear "The Lord has come", but "The Lord is come" is correct. In old English, verbs of movement such as "to go" and "to come" were used with the auxiliary verb "to be" and not the present day auxiliary verb "to have".
Personally, I like to sing "is come," thinking of it in "Already/Not Yet" terms, sort of like the combining of two phrases: "the Lord has come" and "the Lord is coming." Who knows, maybe Isaac Watts had the same thing in mind when he wrote it, i.e., intending for "Joy to the World" to be an Advent song, combining "has come" and "is coming" into one phrase, "is come." Probably not, but I wouldn't put it past him; he was one of the greatest hymn writers in the church's history.
We'll also be holding a good old fashioned hymn-sing Sunday night, with lots of Christmas carols and children singing and a jolly time of relieving the Advent tension pressure valve for a night.
One more thing about Christmas carols during Advent: I heard yesterday that the University of Notre Dame has banned a certain Protestant student group from holding their meetings in the basilica because they were singing Christmas carols during Advent.