《礼记·乐记》
乐的作用是和同，跟随着神而归属于天；礼的作用是辨别差异，跟随着鬼而归属于地。
乐者敦和，率神而从天，礼者别宜，居鬼而从地。
The function of music is to unify, following the gods and belonging to heaven; the function of rites is to distinguish differences, following the ghosts and belonging to earth.