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.

Đò đưa is one of a few folk songs that was influenced by Ca trù and then became a Ca trù song for entertainment. A late Ca trù folk artist, Đinh Thị Bản, said: “This is a favourite song, sung when mandarins were on a boat on Hồ Tây Lake in Hanoi in the past”.

Bắc phản is often played to start a singing session in the environment of Hát chơi (singing for entertainment) and ca quán (singing in the cabaret). The lyrics of the Bắc phản are poems in six-eight-word distich meter. Every six verses of six-eight-word distich meter forms a poem. The first four verses are sung in a Nam tone at a delibrate rhythm; the two last verses are sung in a Bắc tone at a quick tempo that later changes back into a Nam tone with the delibrate tempo. Although Bắc phản song modulates and changes rhythm, its melody is basically stable and pianissimo.