The pen tube is a clarinet air-sounding instrument unique to the Buyi people, named for its slender shape similar to that of a writing brush. Every Spring Festival, March outing or July and a half is the season for the Bouyei people to sing pen songs. In the Bouyei villages on both sides of the Zhangjiang River in Libo County, Qiannan, you can often hear the boys blowing and humming. The pen tube, accompanied by the melodious folk songs of the girls, expressed their incomparable joy.

Since the pen barrel has fewer sound holes, it can only emit four notes, and the sound range is only fifth. Players with better blowing skills can play six or seven notes with the overblown method.

Music workers in our country have reformed the pen tube, and the first eight-hole (the first seven and the last one) pen tube appeared. The pen pipe reformed by Huang Tinghui, a Buyi performer of Guizhou Province Song and Dance Troupe, adopts movable reeds, has nine holes (seven button holes and two key holes), and has a sound range e-e2, reaching two octaves, which not only expands the sound range , but also changed the traditional pen tube reed, tube integration, the shortcomings of the reed damage.