People of the Dong ethnic group perform the Grand Song during a contest in Sanjiang Dong Autonomous County, Guangxi Zhuang Autonomous Region. /CFP

People of the Dong ethnic group perform the Grand Song during a contest in Sanjiang Dong Autonomous County, Guangxi Zhuang Autonomous Region. /CFP

People of the Dong ethnic group perform the Grand Song during a contest in Sanjiang Dong Autonomous County, Guangxi Zhuang Autonomous Region. /CFP

People of the Dong ethnic group perform the Grand Song during a contest in Sanjiang Dong Autonomous County, Guangxi Zhuang Autonomous Region. /CFP

People of the Dong ethnic group perform the Grand Song during a contest in Sanjiang Dong Autonomous County, Guangxi Zhuang Autonomous Region. /CFP

People of the Dong ethnic group perform the Grand Song during a contest in Sanjiang Dong Autonomous County, Guangxi Zhuang Autonomous Region. /CFP

People of the Dong ethnic group perform the Grand Song during a contest in Sanjiang Dong Autonomous County, Guangxi Zhuang Autonomous Region. /CFP

People of the Dong ethnic group perform the Grand Song during a contest in Sanjiang Dong Autonomous County, Guangxi Zhuang Autonomous Region. /CFP

Known as the Kam Grand Choir, the Grand Song is the traditional form of folk music popular among the Dong ethnic group living in Guizhou and Guangxi. This polyphonic musical form features beautiful melodies, rigorous structures and rhyming lyrics and is performed without musical instruments or conductors. This ancient art form has been listed as a national intangible cultural heritage of China and an Intangible Cultural Heritage of Humanity.