To make the chime of bells, an important metal instrument in ancient times bronze as invariably used for the best acoustic effect. Early bells are called yongzhong, rather flat in shape and very much like two concave tiles joined face to face. Later, however, people stressed the beauty of their shape and gave them a more and more round body, at the expense of the tonal qualities.

It seems that there was no fixed number of bells for each chime. Judging by those unearthed to date, a chime may be very simple, consisting of 3,6 or 9 bells, or very complicated, with 13,14,16 or as many as 36 bells.

The most elaborate ancient bianzhong, a set of 65 bells, was unearthed in 1978 inSuixian County, Hubei Province, from the tomb of the marquis of Zeng dating from the Warring States Period (475-221B.C.). Their total weight is over 2,500kilograms, and they were found hung on a three-tiered rack. The biggest of the bells has an overall height of 153.4 centimetres and a weight of 203.6 kilograms. The whole chime, unprecedented discovery in the history of musical instrument ever brought to light----not only in China but in the world as a whole.

Although buried underground for over 2,400years, the bells still produce fine tones. Ancient an modern music, including tunes from Beethoven's Ninth Symphony, reciced ancient tunes of the Tang Dynasty and theme tunes of modern Chinese operas, has been played on them with satisfying results.

Careful study of the bells has revealed that they were cast according to the 7-tone scale with 5 semitones in between, completing a well- integrated system of 12 tones. The scale of the whole chime agrees with the modern 7-tone scale in C major, and its rang covers 5 octaves, just two octaves less than the modern piano. What is more amazing, each bell can produce two different tones, a unique feature in percussion instruments.

An inscription of 2,500 characters engraved on the bells tells of the musical theories and the names of the tones prevalent at the time as well as the positions where the tones can be produced. The unearthing of this set of bells has proved beyond all doubt the application of the twelve-tone equal temperament in Chinese music as early as the 50th century B.C., providing one more evidence of the antiquity of the Chinese civilization.

The 65-bell bianzhong can be seen ate the Provincial Museum of Hubei in the Central China city of Wuhan.

Another bianzhong worth seeing is one of 16 bells made of pure gold during the Qianlong period in the 18th century, now displayed in the Forbidden City's Hall of Treasures. Cast in unique forms and about the same size, the 16 bells are of a uniform height of 23.8 centimetres, but their weight ranges from 4,703 to 14,316 grams. Round in shape, they produce a rather monotonous ring, but they were meant during the heyday of the Qing Dynasty, to impress viewers with the wealth and extravagance of the imperial house. And they are indeed very much valued, being cast in dazzling gold and engraved with lively patterns of ball-playing dragons.