Jeongak (literally “elegant orthodox music”) refers to music played at the Royal Palace, government offices, and local places where people of refined tastes gathered together. As one of the three bamboo instruments developed during the Silla Period (57 BC - 935 AD), i.e., daegeum (large-sized bamboo flute), junggeum (medium-sized bamboo flute), and sogeum (small-sized bamboo flute), Daegeum is the longest among the traditional transverse flutes of the country. It has the emboucher hole at the right end, a buzzing membrane made of inner skin of reed that gives it a special timber, and six holes. Since it makes a wider range of sound than other instruments, it is used as a leading solo instrument. Daegeum-played jeongak covers all kinds of formal ceremonial music, which are all ensembles. It is not known when they started to be played solo. The titles of the pieces of music played by daegeum include Cheongseong Jajinhanip, Pyeongjo Hoesang, and Jajinhanip. Melodies made by Daegeum Jeongak sound delicate but not light, soft but not feeble, and fragile but not shallow.