DAN at Holy Whapping has great suggestions for Advent liturgical life. Of course, it’s a bit late, considering these things often get rolling in October, but parish musicians and their friends: put this in the file.

1. Learn some more hymns. There are many and beautiful Advent hymns besides "O Come, O Come, Emmanuel" and "On Jordan’s Bank." Let’s flip through our hymnal and take a look:
"When the King Shall Come Again" (Gaudeamus Pariter) is one of my favorite Advent hymns, a great text that bespeaks the hope of Advent, set to a great tune that also accompanies the Easter hymn, "Come Ye Faithful, Raise the Strain."
"O Come Divine Messiah" is a beautiful, easy-to-learn hymn from the French tradition.
"Creator of the Stars of Night" and its Latin original Creator Alme Siderum – a great Advent hymn from the Church’s tradition of chant. "Rorate Caeli" and "Veni Redemptor Gentium" are also very good, easily learnable chant hymns.
"Wake, O Wake And Sleep No Longer" and other translations of Bach’s Wachet Auf help engage people with some of the greatest music ever written.
"Savior of the Nations, Come" (Nun Komm der Heiden Heiland) is another great German tune that a good parish organist can also expand on in an improvisation or one of many wonderful settings from Buxtehude to Distler.
"Comfort, Comfort, O My People" is an unconventional, highly chromatic hymn tune, but quite effective.
"Lo, He Comes With Clouds Descending" (Helmsley) is one of the most majestic combinations of hymn and tune ever composed, and is highly recommended to any parish, especially with a good organ. The setting of this to "Saint Thomas" in the Adoremus Hymnal, incidentally, is highly unfortunate. This hymn demands the tune Helmsley, and any other setting is completely inadequate to the majesty of this text