When the circus comes to town, we are accustomed to a certain hierarchy of presentation. First there is the sideshow, often an allee lined with various attractions that are transitory and ephemeral: small, spicy, tender morsels that serve to whet our appetite for the main course, where the real business of the circus -- marching elephants, dancing bears, lion tamers, jugglers, tightrope walkers, aerial acts, the flying trapeze and such -- gets done under the Big Top.