Quan họ singing is a Vietnamese folk music style characterized both by its antiphonal nature, with alternating groups of female and male singers issuing musical challenges and responses, and by the fact that most of the songs in the repertoire deal with topics of love and sentimentality as experienced by young adults.
The style originated in what is now Bắc Ninh Province and was first recorded in the 13th century, and has traditionally been associated with the spring festivals that follow the celebration of Tết (the Vietnamese New Year). Historically, the singing began on the evening before the festival, but today it is much more common for the singing to occur on the main day of the festival.
In general, an initial "challenge phrase" (câu ra) from the known body of songs is sung by a pair of female singers, following which a pair of male singers will respond by selecting and singing a "matching phrase" (câu đối), which must repeat the melody of the challenge phrase. Once they are finished, the order is reversed, and the men will issue their own challenge phrase with a different melody. While in the past the singing was unaccompanied, it is common today for the singers to be accompanied by instruments, whether traditional Vietnamese instruments or modern ones such as electric keyboards.