Trisha Brown original Roof Piece became an emblem of the 1970s for concentrating the spectator attention on far away rooftops. The 2011 dance in the compressed architectural space of the High Line demand that spectators move to see every dancer. The dance reveals how improvised movement by one dancer, viewed across rooftops, is transformed incrementally by distance and jagged lines of vision. The line of dancers starts South and reverses at half-time.