time signature
noun [ C ] uk/ˈtaɪm ˌsɪɡ.nɪ.tʃər/ us/ˈtaɪm ˌsɪɡ.nɪ.tʃɚ/
（乐谱开头用以表示节拍的）拍号
a symbol, usually in the form of two numbers, one above the other, written at the beginning of a piece of music to show how many beats there are in each bar