Zeng Houyi BellsinHubeiProvincial Museum. The set of bells was excavated from the tomb of Zeng Houyi，who was a Warring States duke in Suizhou city in Hubei province. The musical range of the bells， which can carry the main melody as well as the harmony，is more than five octaves. Due to excellent casting and musical performance, they have changed the music history in the world and are honored as a "world rare treasure". [Photo/zhongguociwang.cn]