The celibate, dancing Shakers were once seen as a threat to society – 250 years later, they’re part of the sound of America

Director Mona Fastvold’s new film, “The Testament of Ann Lee,” features actor Amanda Seyfried in the titular role: the English spiritual seeker who brought the Shaker movement to America. The trailer literally writhes with snakes intercut amid scenes of emotional turmoil, religious ecstasy, orderly and disorderly dancing – and sex. Intense and sometimes menacing music underpins it all: the sounds of the enraptured, singing their way to a fantastic and unimaginable ceremony.