One question: why are concert photographers limited to only the 1st three songs? I had to jump through hoops to not only get into this venue but had to be escorted to just leave the press tent and get crowd shots. She's a little passé but luckily her audience were devout fans who for the most part knew all of her songs, word for word.
I learned that if I did this for a living, having a monster 400mm f/2.8 or f/4 ? is a must. I did okay with my 70 - 200mm and a 2X teleconverter.