2. Ancient books recorded that Fuxi made a piano, and there are legends such as Shennong made a piano, Huangdi made a piano, and Tang Yao made a piano; Shun defined the piano as five strings, added one string, and cut one string to add seven strings, which shows that the guqin culture has a long history. According to ancient books, the creation of piano is related to the emperors at the beginning of Chinese civilization. Cao Qinzai: "Fuxi made the piano." It is recorded in the preface to the Qin: "Fuxi's Qin is seven dimensions long." Huan Tan's "New Theory" in the Han Dynasty records: "The Qin of Shennong is made of pure silk and carved from paulownia. When it reached the Five Emperors, it was changed to eight feet six inches. Yu Shun changed five strings, and Wen Wang Gai seven strings.