"I like a bit of song, and dialect is a song. I've never done a proper Brit (accent). I haven't really tried. It would have to be something specific. Irish is lovely for me. But Cockney? Too many people know it too well. You just have to get one misstep... That's an easy one to fall into caricature. Bad caricature." Actor Brad Pitt will never take on a Cockney London accent on film.