Dong ethnic minority villagers take part in a Kam Grand Choir performance during a festival at Sanjiang Dong Autonomous County, south China's Guangxi Zhuang Autonomous Region, Nov. 12, 2016. The Kam Grand Choir is a polyphonic choir that sings by Dong ethnic minority without the help of a conductor or any accompanying orchestra. With a history of over 2,500 years, the Kam Grand Choir was listed as a world class intangible cultural heritage by UNESCO in 2009. (Xinhua/Huang Xiaobang)