The ''xiāo'' is a very ancient Chinese instrument usually thought to have developed from a simple end-blown flute used by the Qiang people of Southwest China. The modern six-hole form of the instrument goes back to the Ming dynasty.
''Xiao'' are today most often pitched in the key of G , although ''xiao'' in other less common keys are also available, most commonly in the key of F. More traditional ''xiao'' have six finger holes, while most modern ones have eight; the additional holes do not extend the instrument's range but instead make it easier to play notes such as F natural. There are a further four sound holes situated at the bottom third of the length of the ''xiao''. The blowing hole is at the top end, usually cut into a 'U' shape. Some ''xiao'' have the blowing end entirely cut off, so the player must use the space between their chin and lips to cover the hole fully. There may be a metal joint between the blow hole and the top finger hole for tuning purposes and sometimes also between the last finger hole and the end. The length of the xiao ranges from around 45 cm to over 1.25 m but is usually around 75-85 cm. Usually, shorter xiaos are more difficult to play because of the need to control one's breath more accurately. The angle to play the ''xiao'' is around 45 degrees from the body.
Varieties of xiao
The ''qinxiao'' is a version of the ''xiao'', which is narrower and generally in the key of F with eight finger holes, used to accompany the ''guqin''. The narrowness of the ''qin xiao'' makes the tone softer, making it more suitable to play with the ''qin'' . It is also the longest of all ''xiao'' types, up to 1.25m.
The ''nanxiao'' , sometimes called ''chiba'' is a short ''xiao'' with open blowing end used in the Nanyin, the local Fujianese opera from Quanzhou.
A separate instrument, the ''paixiao'' is a which was used in ancient China and which, although it remains unusual, has recently had something of a come-back.
The Japanese shakuhachi and ''hocchiku'', and the Korean ''tungso'' and ''danso'' , are descended from earlier forms of the Chinese ''xiao''.