I could see people standing on the tops of buildings outside the stadium, trying to get a free show. It was loud enough for most of San Francisco to hear. During “Stairway to Heaven,” when they got to the line, “There’s a feeling I get when I look to the west,” Robert Plant pointed at the crowd and smiled. The audience let out a cheer. Another memorable moment was at the end of “Stairway.” They brought out a large box and released some white doves. The birds were not that eager to leave and some had to be coaxed out. One dove flew up, but then flew back and landed on Robert Plant’s hand. Jimmy Page put his guitar down and walked over. Plant and Page stood there petting the bird, which seemed very much at home in Robert’s hand