NB: The mutual proportions of the illustrations reproduced here, bear no relation whatsoever to the actual difference in size of the depicted instruments...
There are 4 main types, all of which consist of a so-called wind chest and several pipes with free vibrating reeds, but only 3 types are traditional:
With a gourd as wind chest, and pipes made of bamboo. The natural "handle" of the gourd serves as a mouthpiece.
With a rectangular or tubular wooden wind chest, with 2 rows of bamboo pipes (2 types). The Khên (ແຄນ) shown in the third picture is originally a Laotian instrument,
but it can also be found in neighbouring countries, which have their "local" instruments (of type 1), as well.
With a wind chest having the shape of a cup (or bowl). This classical development of type 1 is at home in China (where it is called Shēng (笙 [IPA: ʂəŋ])),
Japan (In Japanese its name is Shō, which is the Japanese pronunciation of the Chinese (kanji) character), and in Korea (where it is called
Saenghwang (생황 [IPA: sʰɛŋβwa̠ŋ]. NB: Its Chinese (hanja) spelling, which is quite commonly used in Korea, is 笙簧 (Pīnyīn transcription: shēnghuáng).
NB: huáng translates as "reed").
In China we can also encounter modern versions, with bamboo or even metal pipes, some of which can be provided with sound enhancing "amplifiers"
that are made of corresponding material.
In all types with bamboo pipes, each of those is closed at the top with a natural node, and it has an open fingerhole (or thumbhole), which is closed to activate its reed
produces the required tone. In a few cases the lower (open) end of a pipe can be stopped with the right thumb, thus producing a different tone.
Chinese reformed types are fully chromatic, and have up to even 37 pipes, placed in a rectangular wind chest that is provided with a keyboard.
Their shape reminds us of Mediaeval and Renaissance portable organs (Portative; ➺ ill. 6).