It's strange that in a year when the two biggest pop music stories dealt with the renaissances that R&B and dance music are undergoing, we lost icons from those respective genres: Whitney Houston and Donna Summer. Long gone is the time when what those divas brought to their respective genres was fresh and, for that matter, commercially relevant—but the passing of the baton, the out with the old and in with the new, rarely feels so pronounced and tangible.