Dong-wan Kim, of the Silk Road Ensemble, is a master of the traditional Korean janggu. The janggu is an hourglass drum that is the most widely played of all Korean instruments. This drum produces two sounds—one low, one high—symbolizing the harmonious conjoining of male and female aspects. In folk performances called p'ungmul nori, a thin bamboo stick is used to strike the chaepyon (the right side), while the gungpyon (left side) is struck with a round-headed wooden mallet. Some rhythms in p'ungmul nori call for the performer to cross hands and use the wooden mallet to hit the opposite side.