It plays a Christmas song every hour, there are 12 different songs.
Setup: press red button at the back of the clock (or turn to next/previous hour while the clock is still singing) for next song.
I've set it this way:
00:00 Deck the Halls-fa la la la la (18 secs)
01:00 The First Noel (12 secs)
02:00 Joy to the World (39 secs)
03:00 We Wish You a Merry Christmas (14 secs)
04:00 Jingle Bells (47 secs)
05:00 O Come All Ye Faithful (36 secs)
06:00 O Christmas Tree (25 secs)
07:00 Gloria in Excelsis Deo (22 secs)
08:00 O Little Town of Bethlehem (16 secs)
09:00 The Twelve days of Christmas (18 secs)
10:00 Hark! The Herald Angels Sing (39 secs)
11:00 Silent Night (34 secs)