CHARLIE Stemp, 22, has found his breakout role in musical theatre. He plays Arthur Kipps in Half a Sixpence, written by Julian Fellowes, which has been running in Chichester since July.

The production is based in part on the 1967 musical film of the same name, in which legendary entertainer Tommy Steele played the lead role, and also on the H.G Wells novel Kipps: The Story of a Simple Soul.

It tells the story of a young draper’s assistant who inherits a fortune and starts to move into high society, and features classic musical numbers such as Flash, Bang, Wallop!

Half a Sixpence has been lavished with critical praise, with The Argus, The Telegraph and The Evening Standard awarding it five star reviews and commending Stemp’s lead performance. Hailing from Peckham, he jokes that he doesn’t need to fake the London accent of his character.

Hi Charlie, how are you?

We’ve had a lovely couple of days – the shows have been great, the audiences are wonderful, and the sun is shining. You couldn’t ask for any more, really.

What are the days like before the evening show, what do you do?

When we started it was all quite hectic, but now we’ve got used to the shows and settled in it’s more calm. We still do maybe about 20 minutes of rehearsal a day, on various set pieces, but to be honest I try and get as much sleep as I can. It’s quite a physical role for me, so it helps.

Some of those high-octane numbers and dance routines must require more than a little athleticism. Did you have to train beforehand?

It was just training on the job, I think. I’m quite proactive as it is, but my fitness levels were nowhere near what was needed. Especially the big numbers, like Flash, Bang, Wallop! at the end – doing a number like that really helps you get your fitness levels up.

Did you read the positive reviews the show received?

I’m not used to it; I’ve never really had to look at reviews before. There have been none that have been drastically bad and that have slated it, I don’t think. I personally haven’t picked them up, but my dad has. He and my agent seem to message me every time a new one comes out. We’ve mostly had really good, positive reviews. It’s refreshing and wonderful to get that positivity from people, but you have to transfix your mind and do your job.

Can you explain how you came to land the role of Kipps in the first place? You weren’t originally supposed to play the lead, were you?

It was quite an odd experience. Normally when you audition for a show you do it three or four times, but I ended up auditioning 11 times for this one. The sixth round was supposed to be the final. We all knew – because it had gone on the Chichester Festival Theatre website – that a very well established actor called Bryan Dick was going to play the role of Kipps. Unfortunately it turned out he had a contractual obligation to another show (Hobson’s Choice).

I started to think the creative team were being quite specific in their details about why and when they needed me, and then one day I was told I’d got the role. I did backflips in a restaurant.

Is there a lot of pride in the show among the cast and crew? For want of a better term, it feels like it’s become a really big deal in the musical theatre world, and the posters are everywhere.

There’s a lot of pride, yeah. The creative team came out and did this because they wanted to make a new show. However wonderful the original musical was, they didn’t want it to be that. They wanted it to put a new twist on it, which is why they got Julian Fellowes to come in and write an amazing script. It is in essence a completely new show. The creative people in the show deserve a lot of credit. I certainly have a lot of pride in it.

How did you learn the role – through the original music, or novel, or a bit of both?

There was always this fear in my brain of people seeing the show and saying ‘you are Tommy Steele.’ That’s wonderful, and such a good compliment to have, but I’m not Tommy Steele. I’m Charlie Stemp. Tommy Steele made the character, so I couldn’t not be like him completely. I avoided watching the film, but I did read the book.

I tried to make my own character out of parts of the novel. It’s tricky when someone has created a part, and done an incredible job of it. I had to go away and try and think what I could do differently. You don’t want to be someone else’s character. It’s never the same show every night – we like to keep it lively.

How do you learn lines?

Repetition, repetition, repetition. Do it so much that it becomes second nature. There’s a famous quote saying to become a professional at something it takes 10,000 hours of practicing that thing. That’s the way I look at lines. There was a Laurence Olivier quote where he said he needed to read a script 100 times, but once he had done that he knew it back to front. I know a lot of actors read it out in voice messages and listen to it when they sleep.

How did you start acting, singing and dancing?

I went to a school called Belcanto, which was a full time school that did dance in the afternoons. After a couple of months people started to comment and say they enjoyed watching me. I guess when people tell you you’re good at something you start to enjoy it. I always enjoyed acting and worked hard on my singing. When you leave a college like that you leave with such a high level of everything because you’ve been doing it all the time.

You were in the hit musical Wicked, in London, for a while. That must have been intense?

It was an amazing show to do – it’s completely different from Chichester, of course. Wicked is very much ‘this is your track, and this is what you do,’ like boxed musical theatre. Performing to 2,000 people every night and getting letters from people who have watched the shows in seven different countries is crazy.

Half a Sixpence, Chichester Festival Theatre, Oaklands Park, until Saturday, September 3, 7.30pm (matinees at 2.30pm on Weds and Sat), from £15, 01243 781312