It's difficult to put into words, the feeling one gets while standing backstage during a performance. There's little separation between reality and your imagination. One moment, I'm talking to Susan Jaffe about the day's weather.  A second later, I'm photographing Odette and 20 swans dancing on the stage of the Metropolitan Opera House in front of an audience of 5,000. It can't be the same woman I just spoke to. The dancers on stage seem like a dream.