Ping Gong of Jin ordered someone to make a stringed musical instrument. The strings of the instrument were of the same size, with no difference between the small strings and the large string. After the instrument was made. Ping Gong of Jin asked Shi Kuang, an official in charge of music, to tune the instrument. Shi Kuang spent a whole day doing it, but failed to tune out a melody.
Ping Gong blamed Shi Kuang for his incompetence. Shi Kuang explained: "The large string of a musical instrument is like the king of a state, and the small strings are like his subordinates. The large string and the small strings have their own functions. Only by coordinating with one another can they compose temperament, and only by being orderly can they play harmonious and pleasant music. Now there is no difference in size between the large string and the small strings. This ruins the system and regularity which they should have. How can I tune an instrument like this?"