If you thought my nine minutes with Elton John was a bit tight then consider the photographers covering Beyoncé's show at The Q Arena in Cleveland. They were allowed a mere 50 seconds. And not a very good 50 seconds either, according to Scott Shaw, photographer with Cleveland newspaper The Plain Dealer:

She came up in a cloud of mist, and the first 30 seconds she was just standing there. She was silhouetted by backlight, stood still, turned around, and started to sing. She sang like two notes and then a stage hand got up in front of me and said, 'OK, that's it. That's the best shot you're going to get.' And we were out of there.

The paper's director of photography Bill Gugliotta offers this theory:

It's all about controlling their own image, controlling what the public sees. If they limit the photographers to just the first three songs — or the first 50 seconds — they control what costume will be in the newspaper, what background, and reserve everything else for themselves. 

And photographer Lynn Ischay puts that a bit more bluntly:

If they get you out of there early, you don't get any shots after they get all sweaty, and their hair gets stringy and they take off the vests that hide the fat rolls.

Of course none of this can stop thousands of fans taking photos throughout the concert, or recording the concerts on their mobile phones and then posting the video on YouTube when Beyoncé reveals more than she intended to. 

Read the rest of the article to find out what concert photography used to be like when stars were more accommodating. (You can skip the survey screen between pages by clicking the link that says you're outside the US.)
Thanks to Jeremy Harmon for the link.