1. Tchouk Made up of a square box with four outwardly sloping sides and a wooden hammer contained in it, this instrument is used to start the orchestra in the court ceremonies. The box is placed on a wooden base. The handle of the hammer runs through the cover of the box. Along with Eu, another instrument, Tchouk was used in traditional court rites. Introduced into Korea during the Koryo period, Tchouk is now used during ceremonial rites at the Confucian Temple at Songgyungwan in Seoul.