The Hully Gully is a type of unstructured line dance often considered to have originated in the sixties, but is also mentioned some forty years earlier as a dance common in the black juke joints in the first part of the twentieth century. In its modern form it consisted of a series of "steps" that are called out by the MC. Each step was relatively simple and easy to execute; however, the challenge was to keep up with the speed of each step (source).
And for all you crazy cats, here's a YouTube link to a version of the song performed by The Olympics circa 1959, enjoy!
Incidentally, today (April 5th) is my four year geo-versary and I can't think of a better way to celebrate than by hiding a new cache. As always, please cache-in-trash-out, thanks!