I'll answer that A.S.A.P.
Excuse the rather curious start to this post but that's just what the answer is.
Yes, that's right, it's an acronym! As far as I can make out, in the early colonial days in Africa there was a custom when the master of the house (a honkey) was courting a suitable person with which to breed with, he would impress the said subject by showing off his wealth and social standing. Among some of the less bizarre parts of this was the habit of saddling up his manservant (a negro) and, straddling his shoulders on a makeshift saddle, would ride to the potential wife's house. Once there he would parade up and down to show how virile his servants were until the steed buckled or threw him off. The bizzarre stature of the servant with such a dress and weight on his back lead to a similar dance in the night halls where the coloured bretheren would meet up at night sipping moonshine and singing night songs and the name was derived from an abbreviation of what the children would sing "Ride A Golly Til' I' Makes 'Em Marry You'. The 'M' and the 'Y' I think got dropped sometime later. This is why the dance involves such a curious gate and on many special occassions a saddle upon ones back.