probably not what you're thinking of, but the waltz was thought of as outrageously sensual when it was introduced in the late 1700s. Older dances were the sort of formal thing where gentlemen held their hands out for the ladies to spin round - more like line dancing than anything else, I suppose. Then all of a sudden you have young couples of the opposite sex actually embracing their whole bodies as they danced! Scandalous. Somebody said dancing was the vertical expression of a horizontal intention.