Bliss to break-up: Samantha Barks's marriage breakdown stage role

Jonathan Bailey and Samantha Barks play a married couple whose relationship is falling apart

It's eight years since Samantha Barks made her name on the TV talent show I'd Do Anything. It launched a screen career which has included a role in the movie version of Les Miserables. Jonathan Bailey is building a TV reputation with everything from sitcom to intense drama. But they're both happy to be back on stage in composer Jason Robert Brown's intimate two-hander about love gone wrong in Manhattan.

Brown says for him The Last Five Years has always been a highly personal show. When in 2001 it premiered in Chicago, his inspiration had been the end of his first marriage.

"Unlike Jamie in the musical, I'm not a novelist. Nor was I married to an aspiring actress, which is what the other character Cathy is. But the show's take on a relationship going painfully wrong - that was definitely from my life as it then was.

"But perspectives change. I used to think the story was pretty much a tragedy but these days I'm more prone to think Jamie and Cathy will get over what happens to them and maybe they'll even grow stronger. But that would be another show."

Samantha Barks's career was launched on the BBC talent contest I'd Do Anything

Brown is directing his own show in London. "No one who knows me will be surprised if I say I enjoy the control which comes from directing a musical I also wrote," he says.

"But one of the great things about being a composer is that a lot of the time you don't have much to do with anyone else. I don't think I like people enough to direct often.

"But it's a cast of only two. So a lot depends on how the audience reacts to your Jamie and Cathy and that's not something any director can dictate."

Barks says she's known The Last Five Years all her professional life and leapt at the chance to perform in it.

"Obviously it's a smaller show than something epic like Oliver or Les Mis[erables]. But you approach every character from what's written and you make it work. There aren't massive resources on stage but there are big, emotional numbers. And there are fun moments too.'

Brown played an unusual trick with the show's structure. Jamie's story proceeds in the normal way but Cathy's story unfolds in reverse. We meet her when the relationship is already over and then we work back step by step to its origins. "So I'm the one who comes out of the theatre skipping," Barks says.

Samantha Barks and Jonathan Bailey have known each other since working on the Disney Channel series Groove High

"There are moments of extreme bliss like the moment they fall in love - even if it does end with a break-up."

Barks and Bailey have known each other since they worked on the Disney Channel series Groove High a few years ago. "It's great working with a friend like Jonathan because there's a short-hand between you. So if you experiment with something vocally in rehearsal and it doesn't work there's no one judging you."

Compared to his co-star, Bailey has less of a track-record in musicals. "I did American Psycho at the Almeida but it's true I haven't really regarded myself as a singer and I stand in awe of someone like Sam.

"I know actors always say they love a challenge but with this show there really is nowhere to hide - most of the numbers are solos. It's a big sing. You need to be an athlete for it but it works because Jason's songs are full of thoughts and intelligence and that gets you through."

The London production retains the original setting of America in 1993. Bailey says the story wouldn't work if updated to a world where everyone carries a phone around all the time.

Jason Robert Brown won a Tony theatre award for best orchestrations for The Bridges of Madison County

"You need the pressure of Jamie and Cathy being in the same apartment waiting for calls from their agent or whatever - and then his career takes off when he gets a book published.

"It's important we get the New York setting right. There's a real pace to New York life which in reality London doesn't match. And I always have to really work at accents - though Jason's been on hand to ensure I'm not falling into a cliched sort of speech pattern which isn't convincing."

In their twenties, both he and Barks have built up impressive experience on both big and small screens. Bailey was seen this year in Channel 4's hospital-share comedy Crashing and he says it's "distinctly possible" we'll be seeing the W1A team back next year on BBC television.

Also in 2017 he'll appear with Colin Firth in The Mercy, the feature film about lone yachtsman Donald Crowhurst.

'Music theatre is now on the map in Britain in a way it wasn't when I was growing up... there's been a change of attitude, especially in the younger generation,' says Samantha Barks

"When I left school I did far more theatre than anything else and it was exciting. So though I enjoy being on screen, theatre is something I definitely miss.

"Being on stage is a real call to arms - especially in something as exposing as this. It re-sets everything for the actor and your instincts come to the surface again in a way they don't always when you're filming."

The BBC's I'd Do Anything gave Barks a profile she might otherwise have taken years to build, even if she didn't win the contest to find a new Nancy to play in Oliver on stage.

"I'll always be grateful to TV and to that show in particular: for a 17 year-old it was a brilliant start. At the time it was criticised by some in the profession.

"But music theatre is now on the map in Britain in a way it wasn't when I was growing up. Other series like Any Dream Will Do and Glee - and big films like Les Mis[erables] - mean there's been a change of attitude, especially in the younger generation."

In fact Barks's next two films are dramas - Interlude in Prague and Bitter Harvest, which is set in Ukraine in the 1930s. "But for now it's great to be back on stage in a musical: there's a public hunger for them."

As if to prove the point, after our interview it's announced that The Last Five Years will be the penultimate show at the St James Theatre, which earlier this year was bought by Andrew Lloyd Webber. From February he's renaming the venue The Other Palace and plans to make it "the home of new musical theatre".

The Last Five Years plays at the St James Theatre in London from 28 October.

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