According to statistics data in 2009, the Cao Lan people (known as Sán Chay) in Vietnam had a population of 169,410 people, residing mostly in Tuyên Quang province. The Cao Lan ethnic minority has a treasure of poetry, folk music, and dance such as sình ca (unique folk singing), múa trống (drum dancing), múa xúc tép (small shrimp catching dancing), múa chim gâu (cuckoo bird dancing), etc. The musical instruments of Cao Lan people are various, including thanh la (small knobless gong), não bạt (small cymbals), drums, bells, and wind instruments. Kèn is a wind instrument performed in festivals and ritual forms. Kèn consists of four parts: the body, the bell, reed stake, and the reed. The body is a cylindrical hollow tube made of hard wood about thirty centimeters in length. On the body, there are seven pressing holes on the front and one hole on back near the stake. The instrument bell is made of a frustum-shaped thin wooden piece. The smaller of the bell is attached to the big end of the tube. The stake is attached to the small end of the tube. The reed is made of a reed pipe or worn nest attached to the stake. Its sound is strong, a little discordant at high pitches and a little cracked at the low end. The register of the instrument is two octaves. Kèn is played by men only. This track is a medley of extractions that are often played in the rituals, such as hành quân (army operation), kèn Khắp, and đưa Phật (Buddha greeting).

According to statistics data in 2009, the Hmông people in Vietnam had a population of over one million people, making them one of the larger ethnic minorities in northern Vietnam. The Hmông reside mostly in the provinces of Hà Giang and Lào Cai. They have diverse folk music and folksongs. The khèn (or also known as kềnh) is an aerophonic instrument made up of six bamboo tubes of different lengths. These tubes are put through a wooden resonator. The upper part of resonator is small, connecting to another bamboo section that forms a blowing pipe. A small bronze reed is attached at the part put through the wooden resonator on each horizontal bamboo tube. The shortest and the longest bamboo tubes have two parallel reeds, producing unison sound. Pressing holes are outside the resonator. The player covers the pressing hole of the section and then blows air into it to make the reed vibrate and produce sound. Each tube creates a different sound depending on the length and size. The Hmông playing and pressing techniques include clapping, tremolo, and staccato as well as simultaneity, chord, and harmony. Kềnh of the Hmông people is a polyphony instrument with a bit cracked sound. The register of Kềnh is about an octave. The Hmông people blow the Kềnh during entertainment activities, at funerals, or on the way to the market. Traditionally, the instrument is only for men to accompany singing.