故先王著其教焉。
It works deeply on people’s feelings and readily causes customs and morals to evolve; therefore, the sages regarded the teaching of music as a matter of great importance.
夫民有血氣心知之性，而無哀樂喜怒之常。
Since people, let us note, are composed of blood, vital essence (qi), and awareness seated in the heart, there is nothing constant in the way they experience sorrow, joy, pleasure, and anger.
應感起物而動，然後心術形焉。
Only as a response to some external circumstance do their feelings assume some particular form.
是故感激憔悴之音作，而民思憂。
Thus, when weak and piercingly despairing music is performed, then people dwell on mournful things.
When expansive, calm, and flowing music with rich sounds and simple rhythms is performed, then people grow strong and joyous.
嘽諧慢易繁文簡節之音作，而民康樂。
When rough, soaring, haughty music is performed, then people become hardy and resolute.
粗厲猛奮廣賁之音作，而民剛毅。
When music expressive of honesty, rectitude and sincerity is performed, then people become solemn and reverential.
廉直勁正莊誠之音作，而民肅敬。
When expansive, flowing music filled with supple movement is performed, then people become kind and affectionate.
寬裕肉好順成和動之音作，而民慈愛。
When abandoned and licentious music with strong and heady rhythms is performed, then people grow lascivious and disorderly.
流僻邪散狄成滌濫之音作，而民淫亂。
This item enunciates the theory that improper music must be suppressed for the good of the body politic, an idea that has had far-reaching and oftentimes negative effects on music not only in China, but also in Japan, Korea, and Vietnam.
“Music” and “delight” are both expressed in the text by the character 樂, pronounced yue in the first instance and le in the second.