Super Bowl Halftime Show Question

I just watched the Super Bowl again (what a game!), and I’m wondering where all of the kids who rushed the stage during the Tom Petty halftime show came from. Almost none of them were wearing football jerseys, which leads me to believe they weren’t ticket-holders. It looked like a crowd of at least a few thousand.

So my questions are:

Were they given free tickets just for the halftime show? Not seats in the stands, but just for the concert. It’s impossible that the ushers just opened up a few sections, and let the crowd in. Where were all the fat old guys (who are probably bigger fans of Petty than the teenage girls)?

Were they paid to do this? I’m guessing they weren’t paid, just bussed in to a free mini-concert at the Super Bowl. I’d gladly see that concert for free, but I’m not a photogenic young hottie. This is the main reason I think it was staged: everyone looked so young and weren’t wearing jerseys.

If this question has been answered before, even about previous SBs, I apologize. A search on “Super Bowl halftime show” would probably yield numerous nipple discussions, which I’d prefer to avoid.

There’s some info here: http://superbowlcast.com/halftime.html

It’s a volunteer effort, so the payment would have been the privilege of seeing the performance up close and personal.

On the Arizona Cardinals message board, there is this thread which discusses the Super Bowl volunteers for the concert that were recruited in the Phoenix area.