http://www.chnmus.net/hxgy/hxgy1.htm
灰陶埙：商代 安阳殷墟妇好墓出土
Ceramic Blower XU埙
埙Xu is one of the earliest blowing musical instruments. This piece is copied from the ceramic Xu discovered in Anyang (the ancient capital of prehistoric Chinese history Yin Danysty) relics. It is recorded that "Fu Xi burns soil to make Xu", noting that this making has a long history of more than 5,000 years. This Xu on show is in a form of down-to-up spiral, on top there is a round blowing entry, so the Xu is named Pored 5-tone Xu(5-tone五音：宮、商、角、徵、羽 the five notes of the ancient Chinese five-tone scale, corresponding to 1,2,3,5,6 in numbered musical notation), in the near lower part there are 3 sound holes in reverse-triangle form, on the opposite side there are 2 sound holes symmetrically, one larger and one smaller, in the same form and making, which can produce 11 kinds of sounds after sound gauge. According to the findings, this Xu can blow out 7 tones of musical scale, after debugging and formalization in production, this Xu are concording to the requirements of standard tone and absolute pitch. Its tone color is sad as west wind and blowing snows, flying tears and dropping worries. This kind of traditional Chinese close-mouth gas-vibrating musical instrument is maintained for an old age, and continues to lead people to a imaginary land of endless cool sadness.