Air blowing instrument. An ancient Chinese horizontal blowing bamboo wind instrument.
According to the records of "Zhou Li·Zhengxuan Notes" and Chen Yang's "Book of Music", they all say that the chi is a kind of horizontal blowing bamboo wind instrument with 6 holes (including the upper outlet hole) and the bottom end closed. Judging from the two horizontal bamboo wind instruments unearthed from the tomb of Marquis Yi of Zeng at the beginning of the Warring States Period, they are both similar in characteristics to the chi described in the literature, but different from the flute. Therefore, in the Han Dynasty at the latest, Chi and Di should be the same musical instruments with similar pronunciation but different shapes.

In the circulation, the shape of the chi has also changed slightly. According to the notes of Guo Pu, a Jin person in "Erya·Shile", at the end of the Jin Dynasty, its blowing hole had been changed to one 1 inch and 3 minutes higher than the body of the pipe (approximately 3 minutes). 4.3 cm) of the "Qiao" (the so-called "yizui" later) played. Other forms have not changed. According to literature records, almost all of the Chi used in the Song and Ming courts were of this type.
Chi Yuan is a Chinese folk musical instrument. As early as the Zhou Dynasty, it was often played together with Xun. During the Warring States Period, as a member of a large-scale court band, it played with chimes, chimes, drums, xiao (panpipes), sheng, and se, etc. during worship to gods or feasts. The Xianghe song band of the Han and Wei Dynasties also used it sometimes. During the Six Dynasties, with the rise of Qing Shang music, it became the main accompaniment instrument of Wu Sheng. During the Sui and Tang Dynasties, it was a member of the most artistic Qingle band at that time. After the Song Dynasty, it was gradually lost because it was mainly used for court music.

The way of playing the chi can be seen from the wooden figurines made in the Yangjiawan Han tomb in Changsha and the portraits of Yuanhe and Zhanghejian (83-87 AD) in Wuyang, South Shandong. Between the thumb and the index finger, the blow hole and the sound hole are upward at 180°, the left hand's food, middle, and ring fingers press holes 1, 2, and 3 respectively, and the middle and index fingers of the right hand press holes 4, 5.
The performance of the chi can be seen from the sound measurement results of the chi copied from the tomb of Zeng Houyi. Using the simplest fingering method, 6 tones can be played, that is, a complete pentatonic scale plus a changed tone. According to literature records, the Chi in Song and Ming Dynasties used the half-hole fingering method to blow the full twelve laws. Whether the Chi before the Song Dynasty used the half-hole fingering method is still difficult to determine because there is no conclusive proof.