Poor Nina! *hugs*
I don't know what it was like in Moscow, but in St. Petersburg, the city was shut down! There were so many people, the metro was jammed, the streets were blocked-- people had to walk for two hours or more to get home. I'm sure they were doing what your friends in Moscow were-- just getting as close to the square as they could, to hear the music.
Well, you never know. Perhaps you will still see Paul in concert someday. Good luck!