Casting Two-tone Bells in Ancient China: Designs and Manufacturing Techniques

Ancient Chinese bells are possessed of a distinctive acoustic characteristic: a single bell can sound two different tones. An entire set of these bells, a chime-bell set, sounding tones at fixed intervals, has a musical range and flexibility that might be equivalent to an ensemble. These special features, along with the sophistication of musical theories as evidenced by the inscriptions on the bells are exciting yet mysterious discoveries in world music history and archaeology.

This project proposes to examine how the two-tone bells were cast and investigate their design and technical origins. The two-tone quality was not achieved by calculation or devising an innovative bell design; even today this would be very difficult. We hypothesize that the two-tone bells were made by replicating existing bells with already-known tones. The first two-tone bell might have been a chance discovery. But to cast numerous two-tone bells necessitated bell casters’ experience and knowledge of existing bells with known tones. The casters managed to control the sizes, shapes, decorative patterns, and acoustic properties of the bells over years of collecting bells and replicating them. We have identified bells from the Henan area, which are highly similar in size, shape, and tones. These bells might have been replicated, which would have involved various types of knowledge and technical know-how. We will use Henan bells, along with other archaeologically excavated bells, to search for more bells of the same size, shape, and tones. We also will also conduct simulation experiments by casting bells of various sizes. By relying on the assistance of our partner foundries and modern 3D technologies, we will replicate existing bells from collections in museums and archaeological institutes to investigate how their size, shape, and decorative patterns impact the bell tones. We hope to create innovative methodologies and generate new data about the production techniques that were used to make ancient Chinese bells.