Devil Dance is a Western description from the early 20th century for the Tibetan Buddhist ritual dances known as 'cham. They are also known as Chhaam. 'Cham are often performed by monks in costume, and it is from these costumes that the description “devil dance” derives.
Cham are performed to purge, cleanse, combat evil, and bring good fortune, as well as to serve as a means of meditation for the participants.
One iteration of this dance is performed on the eve of Losar, the Tibetan new year to commemorate the assassination of the cruel Tibetan king, 'Langdarma' in the 9th century CE. It is a dance symbolising the victory of good over evil