Fieneke,
Don't worry, we live in Holland. So everything that's not allowed is still allowed. Taking pictures is allowed by the management, so Heineken Music Hall will allow us too. Best thing to do is taking a small camera, put it around your neck or something, it has to be complete visible or complete invisible. Not in your bag, because then they want to check what's in your bag, that takes time and you need every second to run to the front. Better not take a bag inside, put your phone etc in your pocket then they only check the ticket and maybe will search you quickly.
Love
Ingrid