of 2007’s most exciting films is Todd Haynes’ I’m Not There, a movie about Bob Dylan… sort of. A number of actors play Bob at different points in his career, and in the past couple of weeks I have had the chance to talk to two of them.

Ben Whishaw plays the lead in Tom Tykwer’s adaptation of the bestselling Perfume: The Story of a Murderer, and at the junket for that film I noticed he had a button that said: “Chaos is a friend of mine.” The phrase gnawed at me – I knew I had read it somewhere before. It turns out that it’s a Bob Dylan quote, and that Haynes had given the button to Wishaw when he wrapped his segment of the film just a few weeks back. I asked him which Bob he played.

“None of us are really Bob – we’re aspects of him,” he told me. “I’m the poet. I play around 65, 66. I dress sort of like Bob Dylan crossed with Rimbaud. I’m very curious about it.”

Saturday morning I spoke to Cate Blanchett for The Good German, and she mentioned that taking the role of a Bob evoked a different reaction from her. “I’m terrified!” she admitted.

I asked her which Bob she was playing. “Isn’t that the 24 dollar question? Which Bob is Bob? There’s six different Bobs, and I think that’s the greatness of the idea is that he’s splitting Dylan’s persona into so many different ways: into a Woody Guthrie type figure; into a TV evangelist; I play him when he went electric; into an actor; into a 17th Century poet. I think when you juxtapose all those different personas, you get a sense of his spirit… or his shape-shifting.”

Each of the personas have their own section, each of which is approached uniquely. “Mine’s in black and white and I think some of them are hyper-colored,” she said. “Todd is a genre-defying film director to begin with. If you look back to his film school thing about Karen Carpenter with the Barbie dolls, it’s amazing. He thinks so laterally, in such a Todd Haynes way. I don’t think anyone else could have conceived of the idea. It’s great – the fact that I’m a woman, automatically you have that Brechtian distance between the persona of Dylan. The form of the film liberates it from being a biopic.”

But it’s the fact that it might be taken as a biopic that terrifies her. “Even though the film’s aim is not to be a biopic, people automatically will want to receive it like that. Even though I had no interest in imitating Dylan Todd was really specific that I wore the exact suit that he wore in Manchester in 1965, and the hair. He wants those iconic references, but he doesn’t want an imitation, so it was a really difficult tightrope to walk. Which I hope I walked without falling off too often.”