These guys started playing some kind of musical ceremony everytime someone came up the steps to the Mayahana Hall and gave them money. I have no idea what the significance is, though!
Open: 8am-5.30pm. Admission: RMB50
Take bus 6 from the Mountain Resort.
I arrived at the main gate of the Mountain Resort Main Palace at about 8am and walked through, after buying my ticket, and saw a small crowd gathered inside a small courtyard watching some girls dancing in traditional costumes to loud music. I think the dancing was some kind a ceremony to welcome to Emperor to the Mountain Resort as a guy and woman wearing some impressive looking clothes then walked down from behind where the dancers had performed and were greeted by another guy. I have no idea how often this performance happens or what it means but it was a nice surprise, all the same.