This musical instrument is called Khen by The Kinh (Viet) group, while the Mong ethnic minority call it the Kenh, and the Ede in the Central Highlands use a similar instrument called Dinh Nam, etc.
The Pen-pipe may have an evennumber of 6, 8, 10, 12 and 14 sections of small hornless bamboo pipes arranged in two rows. Each pipe is fitted with a reed made of a thin strip of copper. The section of the pipes with the reed lies inside the wooden air-chamber. The part of the pipe lying outside it shows a finger-hole. The pipe into which the player blows lies at right angles with the pipes with finger holes.
The pitch of The Pen-pipe's sounds depends on the the length of each section. The sound of The Pen-pipe is not very clear but quite strong, nonetheless; the deepestnotes are rather dull. Special melodies for The Pen-pipe among ethnicity are composed in the style of homophony.
The Pen-pipe is a musical instrument for men and is used mainly to accompany singing. The H'Mong minority group play The Pen-pipe on various occasions, including funeralswhere it is accompanied by drums. When The Pen-pipe is played by one person, the soloist accompanies the music with dancing in which much vigorous knee-bending, body-turning, kicking, etc., is performed.