During the Warring States Period, Song Yu, a doctor in the State of Chu, was very talented, but the articles he wrote were too abstruse for many people to understand. Some people are dissatisfied with this and say that he is arrogant behind his back. Hearing this, the king of Chu called him in and asked, "People often talk about you behind your back and are not satisfied with you. Is there something wrong with your behavior? You should review well! " Song Yu is very clever and eloquent. He replied, "There is a man singing in the city center. First, he sang popular folk songs, such as "Li Xia" and "Ba people". People are very familiar with it, and thousands of people sing along. Later, he sang songs with profound artistic conception, such as Yang A and Autumn Building, which were sung by hundreds of people. Later, when he began to sing such profound songs as Yangchun and Snow White, dozens of people were left to sing along. Finally, when he sang a tune composed of upper cavity, Henan cavity and Zheng cavity, people all walked away, leaving only two or three people who could understand it to sing along. It can be seen that the deeper the song, the fewer people will sing along. "

Song Yu used this example as a metaphor for his abstruse articles, which some people don't understand, which can only arouse their criticism. The king of Chu had nothing to say.