Fang Xiang, also known as Fang Chen and Bronze Chime. It began in the Liang Dynasty (502-557) of the Northern and Southern Dynasties. "Old Tang Book Music Records": "There are copper chimes in the beams, which are covered with square sounds and the like. Square sounds. Use iron for them, repair eight inches, two inches wide, and round the top and bottom. The large board on the horizontal wood of the musical instrument shelf), leaning on the shelf to replace the bell." According to Tang Fanggan's "Xin'an Yinming House Family Music Fang Xiang": "Gexi iron piece pear garden tune, ear Dingdong sixteen tones"; Tang Niu Shu "Fang Xiangge": "Sixteen pieces of varying lengths, hit the palace merchants all over the place". According to another record in "Zhou Zhengle": "Xiliang Qingle Fang rang, a set of sixteen, with two equal sounds of Huang Zhong and Da Lu."

It can be known from historical records: Fangxiang is composed of sixteen rectangular iron plates, copper or jade plates of the same size, with different pitches of different thicknesses, suspended in two layers, and struck with a small hammer. It is used for court Yan music.

In the Tang Dynasty, Fang Xiang performers such as Ma Xianqi and Wu Bin emerged. Tang Dynasty poets Du Mu, Qian Qi, Yong Tao, Lu Guimeng, etc. all left their poems reciting Fangxiang. In the Song Dynasty, Fang Xiang was less and less used. Now it is only occasionally used in the ensemble of ancient music by the Jinyu Qin Society in Shanghai, and it is on the verge of being lost.

At the end of the 1970s, the Shanghai National Orchestra cooperated with the Shanghai National Musical Instrument Factory No. 1, and successfully developed a new type of forty-three-tone square sound on the basis of referring to ancient documents and the only remaining square sound (made of wrought iron on the sound board). Made of No. 60 steel plate, the top is a rectangle, and the bottom has a prominent triangular sound point. Divided into two rows, they are arranged on a metal rack in a heptatonic sequence. Sound range g1-g4.

In the early 1980s, it was made into a 51-tone square sound. The soundboard adopts twelve well-tempered two-tone scale arrangement, the above is the #c scale, the following is the c scale, and the range is f-c4. The piano frame can be lifted or rotated, which is convenient for playing horizontally or vertically, and is equipped with a damping device and a resonance tube. It can be played solo, in ensemble or as accompaniment to song and dance, and has been officially included in the national orchestra.