Nao [náo], also known as zheng and bell, is one of the earliest percussion instruments used in China, popular from the late Shang Dynasty to the early Western Zhou Dynasty. According to historical records, nao was used to stop drumming when the army was retreating. "Zhou Li" said that "golden cymbals stop drums", which is an instrument used in the army to direct the advance and retreat.

This type of bronze ware, called "big cymbals", is taller and heavier than ordinary cymbals. Most of them were unearthed in the southern region and were mainly used in military and sacrificial activities. Judging from the unearthed conditions of the tombs, it seems that the nao can also be used in conjunction with other musical instruments to be used for feasts or sacrifices. In the late Shang Dynasty, there were three cymbals in a group, which could play simple music and were used as ritual instruments for grand ceremonies. During the Western Zhou Dynasty, there were as many as eight chimes hanging on the rack, which were struck by one person.

There are two completely different shapes of nao in ancient China, which are actually different weapons with the same name. The cymbal in the braided cymbal is a type of bell-like musical instrument. The earliest real object was found in a bronze cymbal with a good face pattern unearthed in Ningxiang, Hunan.
There are single pieces of cymbals, which are arranged in groups and are called braided cymbals. In the tombs of the Shang Dynasty at Yin Ruins, there were once unearthed three groups of cymbals of different sizes, but they could not play complete music.

Over time, this phenomenon has changed. In 1993, a group of weaving cymbals was unearthed in Shigu Village, Fengmuqiao Township, Ningxiang County, Hunan Province. There are 9 pieces in total. Braided cymbals with a large size and a large number of pieces like this are extremely rare.