In the first year of Guanghe of the Han Dynasty, Cai Yong, under the orders of Emperor Ling of the Han Dynasty, published comments on national events, which offended the eunuchs and was sentenced to exile in the distant northern country thousands of miles away. Soon, the court granted amnesty and Cai Yong was released and returned home. The whole family left the desolate snowfield and trekked to the Wuyuan area. Unexpectedly, they offended the then prefect Wang Zhi, so they had to turn south and live a homeless life. Unexpectedly, during this period of wandering, two ancient musical instruments that have been passed down to the world were made - the "Keting Flute" and the "Jiaowei Qin".
Cai Yong’s family moved to Kuaiji. There are bamboo forests here, which aroused Cai Yong's interest in making bamboo flutes to relieve the fatigue of the journey. One afternoon, he went to the bamboo forest alone to pick bamboo materials, but he did not find suitable bamboo materials, so he had to return disappointed. Unconsciously, he came to Keting, and this small and exquisite bamboo pavilion attracted him. He stepped in, looked around, and suddenly started counting the bamboos under the eaves. He stopped when he reached the sixteenth one, stared blankly with his eyes wide open, as if he thought of something, and immediately moved them. He climbed up a ladder and looked at and caressed the bamboo. The more he looked at it, the more he fell in love with it. He shouted, "Brother Wang! Brother Wang! Please take down this sixteenth bamboo for me." Wang Da puzzled. He said: "The pavilion was built yesterday and cannot be demolished! If you want bamboo, there are plenty of bamboos in the forest behind. I will cut them for you." Cai Yong said anxiously: "What I want is not ordinary bamboo, but bamboo with fine silk patterns, round and straight, neither thick nor thin. Look at this bamboo, which has a light yellow luster and black markings, from the inside to the outside. They are all the best materials for making flutes. I have searched all over the bamboo in the forest, but there is nothing this good. Please take it down for me!" Wang Da finally agreed. After the flute was completed, it was indeed extraordinary. Because the bamboo was taken from Keting, it was named "Keting Flute".
Another time, Cai Yong passed through Wu County and saw a porter on the river bank with three wooden sticks tied into a tripod and a large iron pot hanging on it to boil water. After the fire was lit, he went to fetch water. The crackling sound of burning wood emits a unique fragrance of sycamore wood. Cai Yong stepped forward curiously and saw that an old tung wood board was on fire. He quickly pulled out the piece of wood and put out the fire. He held it in both hands and looked at it carefully, unable to put it down. At this time, the porter who was lighting the fire came back and asked Cai Yong why he took out the wood for the fire. Cai Yong said: "Do you know? This is a very good piece of sycamore wood, a good material for making a piano, but you burned it as firewood. Are you willing to sell it? How much does it cost?" The porter said: "Since you are useful, you can Take it and use it.” Cai Yong deeply thanked the porters. When he returned to his residence, he started to carve it into a lyre. Because the tail of the lyre happened to be in the burnt place, he named it "Jiaowei Qin". This "Jiaowei Qin", together with Qi Henggong's "Hao Zhongqin", King Chuzhuang's "Rao Liang Qin" and Sima Xiangru's "Green Pearl Qin" are listed as the four famous Qin in ancient China.