The Phi Mor Dance ritual of the ethnic So in Dong Luang District is performed on the fourth lunar month every year for two days and one night. The purpose of the ritual is to express gratitude and respect to their ancestors’ spirits and to pray to Thaen God for regular seasonal rains to boost the morale of farmers. Changes in the ritual include sacrificial items and the dress of performers. The items and dress are bought from the market instead of being prepared from local materials.