Yak

Yak is similar to jeok in shape, and since the player uses three holes to make 12 tunes, the playing technique is difficult. Yak is used as a kind of dancing tool in royal court memorial service music and sacrificial rites. It is used partly in performance of Munmyo-cheryeak, but when it is played for dance purposes, dancers use this instrument as a set for their dancing, holding it with their left-hand. It has only three holes, so that this makes the instrument difficult to produce 'sibiyul' such techniques as adjusting holes with fingers to a half or a quarter. It is said that the yak was used In ancient time, for instance, the Chou dynasty in China already had it. A reed was made at that time, bur in modern time it is made of bamboo. It would be appropriate to consider the yak as a means for dancers rather than musical instrument.

Jeok

Jeok has one finger hole in the back, five on the front, and two empty holes at the end in the back. At the center of the last joint at the bottom of the bamboo pipe, it used to have a cross hole like ji, but the hole is not carved today. The jeok was introduced into the Koryo dynasty and Currently is Using in Munmyo-cheryeak.