December 6 is the Feast of St. Nicholas. We have celebrated this day by hanging our stockings on St. Nicholas Eve ever since the kids were babies.
There is some music specific to the day. In 1948 Benjamin Britten wrote Saint Nicolas, which tells the life of Saint Nicholas in nine scenes. You can hear samples of the music here at this amazon.com page. The wikipedia entry on him is here.
Anonymous 4 has a CD Legends of St. Nicholas: of Medieval Chant and Polyphony . There is some old English here but most is in Latin. There are readings as well as chants and songs. The booklet included with the CD has the words, explanatory text and some beautiful pictures.
The relics of Saint Nicholas are located in the basilica in Bari.