Mr. Yu is a single-reed gas-sounding instrument of the Jingpo and De'ang peoples. In Jingpo language, "筚" is a general term for air-sounding musical instruments, and "general" means double, which means a pair of air-sounding musical instruments with parallel pipes. Folks have the same style but different specifications.

When playing the sharp left, the pipe body is placed vertically, the mouth contains the main and auxiliary pipes, and the pipe body can also be played horizontally. The thumb of the left hand presses the back hole, the index finger, middle finger, and ring finger press the upper three holes, and the index finger and ring finger of the right hand press the two holes. Breathing and breathing can be pronounced.

The supervisor can play the melody, the sub-pipe makes a sustained tone as a harmony, or the supervisor can be played alone. The main sound range is a-c2, the auxiliary pipe is pronounced as d1, and the main and auxiliary pipe sounds are in a fourth-degree relationship. The sound is clear and beautiful. The fingerings include erasure, glissando, finger vibrato, doubling, up-and-down tone, etc. Skilled performers often use the circulatory ventilation method to make the music uninterrupted.

Sharp left is often used for solo or as accompaniment to singing and dancing. It is a musical instrument often played by young and middle-aged Jingpo and De'ang people. It can be played by men and women, but mostly by men. It is used to express love or play for self-entertainment. Most of the music are popular folk songs such as "Mountain Songs", "Love Songs" and "Songs and Dances".