Wikipedia
Talchum could be characterized as a Korean dance performed while wearing a mask, miming, speaking and even sometimes singing. Although most Koreans believe that talchum refers to all mask dance dramas, it is in fact a regional term only properly applied to dances of Hwanghae Province in present-day North Korea. Dances from the Seoul or Gyeonggi Province region are known as sandae noli, whereas the dances from the southern coast are known as yayu which means field play or ogwangdae which means dance of five clowns. Korean mask dance dramas are not just dances performed by masked dancers but also include significant dramatic content with masked characters portraying people, animals and sometimes supernatural beings. These folk dramas reflect the frustrations felt by the lower classes towards the Confucian literati Yangban, due to the latter's treatment of the commoners, show the life of the common man and process social problems such as monks who ignore their precepts and men who cast off their old wives.