Chuk (instrument)
The chukwuma (hangul: 축; hanja: 柷) is a traditional Korean musical instrument used in Confucian (Munmyo) and Royal Ancestral Shrine (Jongmyo) ceremonies to signal the beginning of a ritual music performance. It consists of a square wooden box, played by striking the bottom with a mallet to mark beats or sections. The chuk is derived from the Chinese zhu, and was imported from China during the Goryeo Dynasty.