Acrobat shows in China have been on the decline. By contrast, “Swan Lake” is hugely popular there. Now an acrobatic troupe has produced a version of the ballet classic, and it’s a hit. “Surprisingly, its acrobatic version of “Swan Lake” has taken China by storm, filling houses in more than half a dozen cities, including more than 30 sold-out performances at the Shanghai Grand Theater, where it premiered last March.”