John Rockwell takes a tour of four American regional dance companies. “To be sure, brief stops at the San Francisco Ballet, the Boston Ballet, the Pennsylvania Ballet and the Joffrey Ballet of Chicago don’t provide enough evidence with which to pronounce on the state of dance in this country. Nor to make sweeping judgments about the companies’ current quality. My visits were partly serendipitous – accidents of travel, not an attempt to set up some spurious battle of the bands. Still, in this sampling, Philadelphia and Chicago came out handily on top of Boston and San Francisco. And all four programs attested to the paradox that everything old can be new again.”