Yu (percussion instrument)
The yu (Chinese: 敔; pinyin: yǔ) was a wooden percussion instrument carved in the shape of a tiger[1] with a serrated back comprising 27 "teeth", used since ancient times in China for Confucian court ritual music. It was played by striking its head three times with a bamboo whisk made from approximately 15 stalks of bamboo, and then scraping it across the serrated back once to mark the end of a piece of music or Confucian service.

The yu is mentioned along with another percussion instrument called zhu (柷) in pre-Qin Dynasty annals; it also appears in the Classic of History.
As used in Korean ceremonial music, this instrument is called eo (hangul: 어; hanja: 敔), and as formerly used in Vietnamese ceremonial music, it was called ngữ (Hán tự: 敔).
The yu was also used in Shao music.