^ Even if it is a technical problem (I would only buy that excuse for I am and Moments actually) many of the vocals were just bad regardless of what the volume was. It really seems like she struggled with the songs that were the loudest - which is understandable. Softer songs and the soft parts of the loud songs her voice came through great. It's a highly coincidental technical problem if her voice is only low during the loud parts of the songs for the whole concert.
I think it would be awesome if she tried to do an accoustic live.