Gregorian Christmas Mass
I happened to attend a Gregorian Christmas Mass with my mother today--it was a totally new experience for me, and it was fascinating. For those who don't know, it's conducted almost entirely in Latin (aside from the homily). The Missal included an English translation so I could follow along, but even more fun was the fact that it contained the plainchant responses in Neumatic notation. It had been awhile since I had to read neumes (since I was an undergrad music major, really) so it was a fun exercise in refreshing an old skill.
The missal had this to say:
The liturgy for Christmas expresses the uniqueness of the day by providing three different Masses, one at midnight, one at dawn, and one in the day; of these, the first and the third are most frequently celebrated. While the mass at midnight is still and intimate, that in the day is festive and public. Christmas is placed on the calendar about at the winter solstice, symbolizing that point when the length of day--the light--begins to increase. This realizes the dictum of St. John the Baptist, "He must increase and I must decrease," with the Nativity of St. John celebrated at the summer solstice, when the light begins to decrease. Midnight of the longest night of the year thus represents life of Him who is God of God, Light of Light. Its obscurity recalls the obscurity of that night in Bethlehem, when, unbeknown to the public world, the Savior quietly arrived in the world, being adored first by humble shepherds, then by wise men. It thus harks back to unseen beginnings in an intimate way; the chants for the Midnight Mass express the mysterious eternal begetting of the Son from the Father.