The daegeum (also spelled taegum, daegum, or taegŭm) is a large bamboo flute that is played sideways. It is used in traditional Korean music. The daegeum has a special buzzing membrane that creates its unique sound. It is used in court music, aristocratic music, folk music, and also in modern classical music, popular music, and film scores. The daegeum has a wide range of notes and a fixed pitch, so other instruments adjust their tuning to match the daegeum when playing together. It is important to know that there are two types of daegeum: Jeongak and Sanjo. The Jeongak daegeum is slightly longer than the Sanjo daegeum and was historically used in court music. The Sanjo daegeum is slightly shorter and was more commonly used by common people in the past. Both types have the same unique buzzing membrane.
Smaller flutes in the same family include the junggeum (Korean: 중금; Hanja: 中笒) and sogeum (Korean: 소금; Hanja: 小笒). These flutes no longer have a buzzing membrane. Together with the daegeum, they are called samjuk (Korean: 삼죽; Hanja: 三竹), which means "three bamboo," as they were the three main flutes during the Silla period.
A solo performance called daegeum sanjo was recognized as an Important Intangible Cultural Property of Korea by the Cultural Heritage Administration of South Korea in 1971.
According to Korean folklore, the daegeum was invented when King Sinmun of Silla was told by Park Suk Jung, his ocean caretaker, in 681 that a small island was floating toward a Buddhist temple in the East Sea. The king asked his sun caretaker to check if this was a good omen. The caretaker said that a dead king who became a sea dragon and two great warriors were giving a gift to protect Silla. If the king visited the sea, he would receive a priceless gift. The king sent someone to find the gift. The person reported that a bamboo tree on the island changed from two trees in the morning to one tree at night. The next day, the world shook, and it rained heavily for a week. When the king went to the island himself, a dragon appeared and told him that if the bamboo on the island was cut down, made into a flute, and played, the country would be peaceful. The king cut down the tree, and the flute made from the bamboo was named manpasikjeok (Korean: 만파식적; Hanja: 萬波息笛).