Addendum to my last post:
I forgot to mention that Iron Maiden lost power to their soundsystem halfway through the show. It happened with about 20 sec remaining in a song. Obviously they had their amplifiers cranked to 11, and it was just too much for NYC.
So what did the chaps do? They kicked a soccer ball around the stage to keep us entertained during the intermission. :) YouTube - Iron Maiden loses power @ MSG
Here's another clip, this time with the sound system working: YouTube - "Run to the Hills" @ MSG