I'm unlikely ever to have a priceless oil painting hanging on the walls of my flat, but at Kenwood House the walls are crammed with Old Masters. With summer at last here (I'm convinced the sun is a magic ingredient that will cure our current economic ills), I decided it was time to venture again to this London landmark on the edge of Hampstead Heath. I hadn't been for years. Kenwood is one of those places we know is there, and we know it's pretty, but it just seems a bit too far away. Fighting through the traffic (which I've decided it's still OK to blame Ken for), I remembered an article I'd read that Russian scientists have discovered that loud music can knock years off the life of an old painting. As Kenwood regularly hosts rock concerts during the summer, I wondered how its Old Masters were faring here in the careful hands of English Heritage, which is supposed to 'protect and promote England's spectacular historic environment'. More of that later.