You have to be kind of alerted to the fact that clowns are scary and then you can't look at them the same way again. There's something very sinister about them... There's something very tragic about them as well. The last thing they are is funny.

Audiences are very sophisticated and they know the nuts and bolts of the genre - certainly with horror more than others I think. But they attract lots of people, they're much derided as a genre but people go and see them and they're not all dumb. There's some very clever horror films. Stephen King gets a lot of flack for not being a proper writer because he's a horror writer, but I think he writes some brilliant books. I think it's wrong to just bin it before looking at it.

But live you get the chance every night to rework it and change it and hone it. But then you get the false, weird oddness of being able to look at it and say: "Well that's weird, because last night they laughed at that and yet they didn't tonight. So what did I do? Nothing was different." You have that strange thing of being able to tell within five minutes what an audience is like. Very quickly an audience gets a personality and you start to think: "What is it about you all; you all hate it, don't you?" Then you come out and have friends in and they say: "It was brilliant!"

It's such hard work doing a musical. I did my first musical last year, performing in The Producers, and it was a big part to suddenly be doing Leo Bloom in that. It's such hard work. It's a proper slog. It became like clocking in. And it's a big factory - you go in, everyone's got their little plot, people are taking in and out of it if they have days off or holidays, and it's just a jigsaw that all works. It always amazes me that this product would happen every night and it was just all these elements coming together in a big machine.

Live theatre is great. I loved doing the League live because you get that element of spontaneity, but then when I'm doing live I start to crave the precision of filming. It's a different discipline; it's like a scalpel and you're very precise suddenly. It's scary as well because you think this is it, this is my one go at making it if I can the best it can be, because this is how it's going to be remembered and rendered and left on this film indelibly. And people are going to look back on this and that's that.

You have to be kind of alerted to the fact that clowns are scary and then you can't look at them the same way again. There's something very sinister about them... There's something very tragic about them as well. The last thing they are is funny.