Mummer, the album by XTC, refers to what kind of folk play?
Mummer (album):  The album title refers to a Mummers play. Mummers play: Mummers' Plays are folk plays performed by troupes of amateur actors, traditionally all male, known as mummers or guisers (also by local names such as "rhymers", "pace-eggers", "soulers", "tipteerers", "wrenboys", and "galoshins").
Mummers' Plays