By anyone's estimate, December is a heavy-hitting month on the social calendar. The weekend of December 14th and15th, The Kimmel Center of the Performing Arts opened its doors to Philadelphia royalty and loyal subjects, with celeb concerts by Elton John, singers Denyce Graves and Frederica von Stade, cellist Yo Yo Ma, pianist Emmanual Ax, violinist Itzhak Perlman and of course, our own beloved Philadelphia Orchestra. On Friday, after Elton John belted out the last song in his hour-long showcase, the Kimmel Center was open for everyone's perusal. There were scrumptious buffet stations set up all through the vast hall and circular corridors. On Saturday, post-concert and pre-dancing, we sat down to a spectacular four course dinner with wine pairings. The must-see of the weekend, other than the women's luxurious dresses, the soaring expanse of the concert hall and the rushing hither and thither of the guests, was the rooftop garden under the stars. The giant glass dome reaching over the top of it makes one feel as though they might be plucked from their table by the Man in the Moon at any moment.