to indicate the pronunciation of Chinese characters using Pinyin or Bopomofo etc / phonetic notation / (specifically) Bopomofo (abbr. for 注音符號|注音符号[zhu4 yin1 fu2 hao4])
简谱
jiǎn pǔ
music notation in which the notes Do, Re, Mi, Fa, Sol, La and Si are represented by numerals 1 to 7