Jessica Lang Dance, waltzing delightfully with Leila Josefowicz and the NSO
There were so many ways the musicians could have upstaged the dancers at Friday's performance of Jessica Lang Dance and the National Symphony Orchestra. The Kennedy Center's Concert Hall stage was full of action before the dancing even began, starting with the take-charge physical presence of Leila Josefowicz. The tall, glamorous guest violinist strode onstage in a gust of black silk as if she carried her own weather…