If the Dancer Dances

Stephen Petronio, one of today's leading dance-makers, is determined to help his dancers breathe new life into "RainForest," an iconic 1968 work by choreographer Merce Cunningham. With help from three members of the former Cunningham company, Petronio's dancers strive to restage this work, revealing what it takes to keep a dance -- and a legacy -- alive.