just put your camera in your cell phone case. I've been through metal detectors at concerts when my camera set it off, and I just told them it was my binoculars. Just don't go in through someone that looks like an offduty cop or a school teacher, they take their duties way too seriously. Go through guys that look like they go to concerts all the time.
Also, you can always put it in someone's purse. Then they put it inside a kotex, believe me they don't mess with that, none of them. U2 has been telling them to let us bring our cameras in I thought.
I always record concerts I go to, and I put the recorder in my purse in a zippered place they don't see, it's covered by a flap, and I always buy a new purse that is identical so I always have one. Again, always make sure to go through people that look like they go to concerts, not old retired Marines or offduty cops.
Also, before you go in, you should always watch what the particular people at each entrance are doing, and how closely they do it, or how nasty they are, and get a purse, it works wonderful.