Chen Collection, Middle Volume. Radical: Tree (mù). Kangxi strokes: 9. Page 521, Entry 09. Pronounced chu (falling tone). Shuowen Jiezi (Explanation of Simple and Compound Characters): A musical instrument made of wood that is hollowed out, used to stop the music and mark the tempo. Classic of History (Shujing), Chapter on the Plans of Yi and Ji: Combining them to stop the music with the zhu and yu. Commentary: The zhu resembles a lacquer bucket, two feet four inches square, and one foot eight inches deep. It contains a mallet handle that reaches the bottom, which is moved from side to side to strike the inner walls. Guo Pu stated: At the beginning of a musical performance, one strikes the zhu to initiate it; at the end of the performance, one scrapes the yu to cease it. Also pronounced zhu (falling tone). The meaning is the same. Also, a type of tree. Erya (Approaching Elegance), Chapter on the Interpretation of Trees: The zhu is a tree of the Zhou region. The mao is a soft flowering tree.