That's quite a day out. I don't think I've been to Rotterdam since I was a kid. Preserving all the old art and antiques must be difficult and I think a lot of museums have warehouses full of stuff. Even humans breathing in the room can do damage.
That's a contrast to the music show. Looks like you really enjoyed it.
Rock on!
!BEER
Yes , you don't realize (at least I didn't) that every breath or change in temperature can really harm stuff. It was a great day with a lot of different impressions :)