Acoustics are the essential requirement of bell casting. As the basic shape of a Chinese bell, the ratio of the height to the rim diameter is about l:0.7, while the ratio is about 1:1 for a Western bell. The Chinese bell produces deep and melodious notes. The Western bell produces short and sonorous notes. The strokes of bells contain profound national, regional and cultural connotations. The Chinese determined the choice more than 2,000 years ago. Yet we can learn more from the Yongle Bell. The thicknesses of the bell vary regularly. The waist of the bell is relatively thin and the lower part of the bell grows thicker and thicker toward the rim. The varying thicknesses of the bell make it produce deep and melodious notes and enhance the harmonization of the timbre.
