Bian Zhong consists of bells of different sizes that produce hollow sound of different pitch.
Its origin can be traced back to 5000 years ago when the first Clay Zhong was manufctured. In Shang Dynasty, Copper Zhong was made. In Xi Zhou Dynasty, it became an important instrument in playing music for the Emperor. Since it was an instrument for the Emperor, the Carvings on the Zhong was done beautifully.
In Chun Qiu Zhan Guo, many Zhongs of different sizes and pitch were grouped together and were hanged on the wooden rack. There were 6, 7, 8, 9, 13, 14, 16, 36, and even 65 Zhongs being grouped together.