The Nuo opera: a "living fossil" performed in masks
Nuo (nuó) is the ancient rite of expelling pestilence and ghosts, attested as "the villagers' Nuo" in Shang and Zhou times. Later, song, dance, plot and roles entered the rite, and it evolved into Nuo opera: performers wear carved wooden masks, and the mask is the role — mask on, a god; mask off, a person.
Nuo troupes still perform in Guizhou, Jiangxi, Anhui, Hunan and elsewhere, and are called "the living fossil of Chinese theater." Their preciousness: the step from ritual to drama is a transition Nuo opera still preserves in the act.