The bamboo mouth organ (Lao: khaen) is considered an identity marker of the Lao. Men belonging to other groups residing in Laos, such as the Katu living in the southern region, also play the khaen. The khaen is also found in areas where the Lao live, such as neighbouring Cambodia and Thailand. This instrument is related to the Chinese sheng, which is the root of the harmonica.
The khaen is composed of pairs of bamboo pipes of descending lengths that are connected via a hollow wood reservoir or carved wooden windchest. The windchest serves as the mouthpiece in which air is blown. A free reed composed of brass or silver alloy is in this reservoir. Each bamboo pipe has a reed. A hole is burned in each pipe above the windchest. An instrument maker utilises insect resin, khii suut, as an adhesive, and a vine, kheua na nyang, as a binding. The mouth organ is named after the number of pairs of pipes. Most common type of instrument consists of sixteen pipes or eight pairs (Lao: khaen paet).
The khaen has pentatonic scales and is traditionally played for special occasions, such as weddings, and festivals. In the past, festivals featured pairs of singers and khaen players who improvised while performing. Khaen music has been incorporated into modern folk music, which is called luuk thung in Thailand and features musicians of Lao descent. Foreign musicians have also taken up the instrument.
Hmong musicians also use a free reed mouth organ (Hmong: qeej or gaeng). The bamboo pipes composing a Hmong mouth organ can be slightly curved or straight. When played, the music resembles Hmong language. Each note is a word. Thus, the Hmong qeej player is a storyteller, dancing or moving while blowing into the instrument. Sometimes, the windchest consists of a dried gourd with a long tapering neck. The Hmong mouth organ is also played during ceremonies, especially funerals, and festivals. Several musicians often play together.
Musicians produce instrument for personal use and for sale, bringing examples to demonstrate and sell at large events, such as Hmong New Year. Both the Hmong and Lao diaspora buy the bamboo organs to play in their countries of residence. Mr. Pa Kao Yang is a qeel musician who sells his instruments in the Phonsavanh Market of Xieng Khouang Province. Other musicians sell at large festivals such as Hmong New Year.