《礼记·乐记》
所以，乐可以说是天地之间最能合同的东西，是协调世间万物的纲纪，是人情不可缺少的东西。
故乐者天地之命，中和之纪，人情之所不能免也。
So, music can be called the most uniting thing between heaven and earth. It is the principle that coordinates all things and is an indispensable element of human nature.