The danso (also spelled tanso) is a Korean notched, end-blown vertical bamboo flute used in Korean folk music. It is traditionally made of bamboo, but since the 20th century it has also been made of plastic. It is imported from china in 19th century, where it is called duanxiao.
The instrument is derived from the Chinese xiao and is used as an educational tool in Korean primary schools, much like the recorder is used in western nations.
The flute has four finger holes and one thumb hole at the back. The playing range is two octaves, going from low G to high G. The lower sounds are made by just blowing, whereas the higher ones are made by difference in the strength of the blowing.