Like his "still point in the turning world," the speaker's dancing imagery is also his way to fuse all of the contradictions he's trying to bring together in his vision of a better spiritual existence. This is because dancing is constant movement, right? But at the same time, it's movement that doesn't lead you in any direction, like jogging does. It's totally movement for the sake of movement, and it plants you in the present moment, which helps explain why so many world cultures incorporate dancing as part of spiritual rituals. In this case, dancing is a great image for the speaker, since it fuses the opposites of body and spirit and absorbs passing time into a constantly "present" moment.
54: "The dance along the artery"
66-68: "there the dance/ is,/ But neither arrest nor movement"
73: "There would be no dance, and there is only the dance"
164: "The crying shadow in the funeral dance"
210: "And see them dancing around the bonfire"
273: "The dancers are all gone under the hill"
306-307: "So the darkness shall be the light, and the stillness the / dancing"
788: "Where you must move in measure, like a dancer"