How long has it been since a dance changed the temperature of a Broadway show?

In Daniel Fish’s unnerving production of “Oklahoma!,” the second act opens with a rumble of electric guitar. Its brooding, sexy sound fills the space until a familiar melody takes over: “Oh, What a Beautiful Mornin.’”

But is it really a beautiful day? By this point, a fog machine has created enough haze to sink a ship.

And then comes an odd yet arresting sight: A dancer, Gabrielle Hamilton, walks to the center of the plywood stage. She lingers long enough to gaze at audience members, who ring the performance area on three sides. Soon she sets off, galloping around the perimeter with her hands in front of her body crossed at the wrists. Her glittering white top grazes her mid-thigh and reads “Dream Baby Dream.”

For the show’s choreographer, John Heginbotham, the shirt is an instruction for the viewer. As he put it in a recent interview: “Please, now, take this time to dream.”