I know something about being at the coalface - Kenneth Cranham on The Father
I know something about being at the coalface - Kenneth Cranham on The Father
© Simon Annand

Kenneth Cranham stars as 80-year-old ex-tap dancer Andre in Florian Zeller's remarkable and ambiguous play which astonished critics at its London run at the Tricycle in May. Featuring a witty and devastating performance from Cranham, the play puts the audience in the confused shoes of Andre, who is increasingly unable to tell whether he can trust his own daughter. The Father opens in its West End transfer this month.

You've been touring The Father since it opened in Bath in 2014…

Yes, last Friday was my 100th performance. I've only got Rebecca Charles who's been with me all the way through. But I know something about being at the coalface because I was the inspector in [Stephen Daldry's 1992 production of] An Inspector Calls 800 times.

The play really keeps you guessing in the first hour – how would you describe it?

Someone I know works with people with Alzheimer's and he says it's the best demonstration and explanation of Alzheimer's he's ever seen. But I really try and make the thing as funny as I can, because my character Andre hasn't got any filters, he hasn't got anything that prevents him from saying whatever he thinks. Which is funny, if also dreadful and hurtful at the same time. The play is almost like a piece of music. Certain phrases repeat themselves and although there's a strong feeling of reality about it, it's also like a dream.

Was it harder to learn the cues and dialogue because of the repetition?

Bits of it are very difficult. Now we're going into the West End we have understudies and it's interesting because mine is finding the same parts difficult that I did. Which is good because it shows that I'm not getting Alzheimer's!

Did you ever worry whether people would pay to see a play about Alzheimer's?

You can imagine people saying ‘we're going up to the West End, what would you like? A soap opera about the royal family, a musical with songs by the Kinks or a play about dementia?' I do wonder what sort of commercial existence it's going to have. It was very sought after when we did it at the Tricycle Theatre [in May]. There's such variety in response to it.

The play and French playwright Florian Zeller aren't well-known in this country, what made you want to take on The Father?

I was recently in Rory Kinnear's debut play The Herd where I played somebody who couldn't get in and out of the chair unaided. And before that I was Firs in The Cherry Orchard [in 2011] so this makes up a trio of decrepitude! This is the hat-trick. But each of those pieces really moved me and I think my favourite thing to happen to me as an audience member is to be moved.

Andre is an emotionally challenging part. Do you come off exhausted?

No actually, I think you'd have to pay quite a lot of money for this sort of therapy! But it is a very delicate performance. A few nights ago a woman was fanning herself with a programme because she was hot, right in my eye-line, and I just was thinking ‘don't do that, you're disturbing everyone around you, you're disturbing me, it's just daft'. You can be so easily distracted.

You've done a lot of TV and film as well as theatre. Do you find changing between them easy?

I've been acting since 1964, early in my career I was in 13 productions at the Royal Court on £15 a week, so I would do television and that would pay my bills. I think the mediums are more similar than dissimilar. A lot of what I do in The Father is not unlike film acting. Obviously if you're in a 2000 seater or something you so need to lob it out a bit more. Which I'll have to do at Wyndham's.

You've never really stopped working since you started acting 50 years ago…

My theory is that you have a young career then a dad career and then an old career. They're the three ages of an actor. I'm in the old one now but the problem is all the actors in their 60s, 70s and 80s are all in the same sheep pen as you.

The Father runs at Wyndham's Theatre from 5 October to 21 November 2015 (previews from 30 September)