After the debacle over who owns Martha Graham’s dances, other choreographers have begun thinking about what will happen to their work when they die. Paul Taylor and Merce Cunnigham’s plans are “as much a reflection of their singular personalities as are their dances and the troupes each has molded for more than half a century. Mr. Cunningham has made at least 150 dances since founding his troupe in 1953; Mr. Taylor has composed 125 works for the company he created in 1954.”