As for the soundtrack, it's become one of the best selling Christmas albums of all time. "Christmastime is Here," composed expressly for the special, has become a holiday standard, and "Linus and Lucy" has become arguably the most popular jazz instrumental in history. (In my estimation, only Dave Brubeck's "Take Five" comes close.) Here are a pair of tunes from the soundtrack, one an arrangement of a familiar Christmas carol, and one composed for A Charlie Brown Christmas by jazz pianist Vince Guaraldi.
Vince Guaraldi Trio - What Child Is This? (MP3, 1.7 MB)
Vince Guaraldi Trio - Christmas Is Coming (MP3, 2.4 MB)
Previous Advent posts:
2003: Christmas
2004: The Adoration of the Shepherds
2005: Comfort and Joy
2006: from About a Boy
2007: Madonna and Child