I wanted to do a quick addendum to the post I did about a month ago on finding out publicist contact info. That was dedicated to finding the publicist for a band. But there's a key person I completely left out. While I like contacting the publicist directly, what if you can't find them? What do you do? Well, contact the promoter of the show! They'll have direct access to the publicists and can help you get a photo credential.
So that begs the question, how do you find out the promoter? Around here, it's a lot by venue, and there's only two main promoters (AEG or Livenation). Call up the venue, ask them who's promoting a particular show, and more often than not, you'll get a phone number. Then you have a direct line to the promoter to phrase your request. Call the number, they'll probably give you an email address. For the local AEG affiliate, they even said I can email any of the promoters in the office (there's apparently only three), and they'll forward it to the correct one, assuming it's an AEG show.
The downside I've found with this is that the promoter will normally not find out until the day before or the day of the show if they can get you a photo pass, so you need to be willing to move at a moment's notice. I haven't had that experience with the publicists - I've known normally a couple weeks in advance. But the two times I've contacted a show's promoter I've found out that day if I got cleared or not.