you commented on a film clip used by The Black Ryder band for a song called "Let It Go". The film is a performance of "Jathilan" I have seen in Central Java.
"Jathilan is a Javanese folk dance that uses the power of music and dance to channel powerful and sometimes terrifying forces. Led by a spiritual guide and a whip-bearing ringleader, a group of dancers ride woven horses in rhythmic unison until spirits enter them. Once possessed they engage in a range of self-mortification behaviors."