Music itself should not be divided into joyful music and sad music – it can only accommodate or inspire feelings. This idea was first raised by Ji Kang (223-262 or 224-263) of the Three Kingdoms period. Ji held that music should be separated from emotion and aspiration. Emotion and aspiration, he said, are controlled by the soul and show themselves in many musical forms. The feelings or aspirations expressed by a musician are different from those evoked in the listener’s heart. The relation of music to the governance of a country is that rulers should first know more about the livelihood and aspirations of ordinary people and then moralize them accordingly. Musicians can incorporate truths, wholesome aspirations, and noble ideals into harmonious and beautiful music, linking music to certain implications cementing among the audience a broad consensus so as to exert positive impact on the popular belief, improve social customs, and in the process further strengthen messages implied in the music. This theory of non-differentiation between joyful music and sad music urges literary critics of later generations to examine a combination of factors such as historical changes, social customs, the inner worlds of authors, and the psychological reception of audiences, and to understand the essence and functions of art and literature more rationally.

Music should be judged on the basis of whether it sounds pleasant or not. It has nothing to do with men’s joy or sorrow. Men’s joy or sorrow is evoked by actual events; it should not be directly linked to sounds. (Ji Kang: On Non-differentiation Between Joyful Music and Sad Music)

Sad feeling, buried in a grief-stricken heart, will burst forth through musical melodies. Musical melodies have no fixed form, whereas sad feeling is controlled by the heart. (Ji Kang: On Non-differentiation Between Joyful Music and Sad Music)