This is a Zhong Bell. It is believed that these instruments were in use in China between 3,500 and 2,000 years ago. They're usually found in groups of odd-numbered sets. The Zhong bell does not have a clapper inside, but instead is played by striking it with a mallet from the outside. In 1957, a group of Chinese musicians found that each bell could play two notes, depending on where the bell was struck. Photo by Donald Fink.