Is it ok to tamper with other people's work?

From cover versions to fan fiction, we live in age of appropriation.

You can make big money from tampering with other people's work.

But should you? And, where do the boundaries lie? Picasso said "good artists copy, great artists steal" - but that's isn't always a winning argument.

Will Gompertz discusses this - and Fifty Shades of Grey - in his latest blog.

Filmed at the Cinema Museum in Lambeth, London