葛利果聖歌欣賞

這些曲子的影像是早期的樂譜,
http://www.youtube.com/watch?v=2HEKhr002Ts
http://www.youtube.com/watch?v=lkpFB6urAEE&NR=1
http://www.youtube.com/watch?v=GfbITZgBZzs&feature=related