The North Sea Jazz Festival
at the biggest concert venue in Holland (Ahoy Arena) states the following:
"You can bring a small camera. Only when you are accredited as a press photographer it’s allowed to bring professional photo / film cameras to the festival."
Nice and vague. So the first year I went I had the GF carry my trusty old S2IS (got to love a camera that runs on AA batts) and Pana LX3 in her handbag, and I left my 40D & L glass at home & took a small prime mounted on her 350D in my satchel, with her 55-250IS crammed inside my folded-up bike poncho.
Of course once I got in I saw a dozens of people carrying 5DIIs and various 70-200s in the open with no press cred or photo pass whatsoever, ho-hum. Still got plenty of good shots & movies anyway. There were certainly a few performances where photos by anyone without press cred were strictly forbidden, & the ushers were enforcing it (mostly the shows with assigned seats you had to pay extra admission for though).