1. The apartment of 2 psychiatrists.
2. The lad is a diminutive percussionist.
3. Decorate the entry-ways.
4. Sir Lancelot with laryngitis.
5. A B C D E F G H I J K M N O P Q R S T U V W X Y Z.
6. Present me naughty but dual incisors for this
festive Yuletide.
7. The smog-less bewitching hour arrived.
8. Exuberation to this orb.
9. 288 Yuletide hours.
10. Do you perceive the same longitudinal pressure
which stimulates my auditory sense organs.
11. The red-suited pa is due in this burg.
12. Stepping on the pad cover.
13. Uncouth dolt has his beezer in the booze and
thinks he is a Dark Cloud's boyfriend.
14. Far back in a hay bin.
15. Leave and do an elevated broadcast.
16. That exiguous hamlet south of the holy city.
17. Behold! I envisioned a trio of nautical vessels.
18. Listen, the winged heavenly messengers are
proclaiming tunefully.
19. A joyful song relative to hollow metallic
vessels which vibrate and bring forth a ringing
sound when struck.
20. As the guardians of little woolly animal's
protected their charges in the shadows of the earth.

The only one i knew was #3!! (And i wasnt quite sure until i scrolled down and checked :icon_cheesygrin:)

Here are the answers:

1. The Nutcracker Suite
2. Little Drummer boy
3. Deck the Halls
4. Silent Night
5. Noel (No L.)
6. All I want for Christmas is my two front teeth.
7. It came upon a midnight clear
8. Joy to the world
9. 12 Days of christmas
10. Do you hear what I hear
11. Santa Claus is coming to town
12. Up on the house top
13. Rudolph the red nosed reindeer.
14. Away in a manger
15. Go tell it on the mountain
16. O little town of Bethlehem
17. I saw three ships
18. Hark the Herald angels sing...
19. Jingle Bells
20. As Shepherds watched their flocks by night

Where did you get those titles in the first list?

Number 5 had me laughing for a minute there :D