Loop Suspension Bell (Niuzhong), Eastern Zhou dynasty, Spring and Autumn period (770–481 B.C.), 8th/6th century B.C. Bronze, 34.8 × 19.9 cm. Samuel M. Nickerson Endowment, 1923.1113 © Art Institute of Chicago 

Several types of chime bells were cast toward the end of China’s Bronze Age and were probably played together in concert. Smallest among these were niuzhong, which had concave rims. Niuzhong were cast in graduated sizes, assembled as a set (often of nine), and suspended from a horizontal beam in order of size. Each bell was designed to emit two distinct tones: one from striking the center of the lower panel, another from striking either corner. The mask centered on the striking panel of this bell is an abstraction of ferocious monster designs seen on earlier bronze vessels.