John Partridge is currently starring as the formidable director Zach in A Chorus Line, which opens to press at the London Palladium next week (19 February 2013, previews from 5 February).

The revival - the first major production of the 1975 show since composer Marvin Hamlisch's death last year - is directed by Bob Avian, who also helmed the 2006 Tony-nominated Broadway production. Avian was original director Michael Bennett's long-term collaborator and his co-choreographer on the original production.

Partridge, best known for his role as Christian Clarke in EastEnders, has appeared in numerous musical theatre productions including Cats, Starlight Express, Tommy, Grease, The Drowsy Chaperone, Rent and Miss Saigon. He is regularly seen presenting the National Lottery programme and in 2010 he joined Andrew Lloyd Webber, Charlotte Church and Sheila Hancock as a judge on BBC1's Over The Rainbow.

He stars in A Chorus Line alongside Scarlett Strallen (pictured with Partridge) as Cassie, Leigh Zimmerman as Sheila and Victoria Hamilton-Barritt as Diana.

John Partridge: When I was initially approached about doing A Chorus Line, I wasn't necessarily attracted to the idea because I didn't know if I wanted to go straight into a musical after being in EastEnders. Plus, I had never seen it on stage - I had only seen the movie. I didn't really have any idea what the stage show was like besides the script.

Then I went for a meeting with Bob Avian in which he explained more about Zach and the many different ways to play him, and from that moment on it grew on me. The more I thought about it and read the script the more I realised it was absolutely the right project at the right time - professionally as well as personally. Couple that with the chance to work with people of the calibre of Bob and there aren't many people who wouldn't want to shake their money-maker on this project.

In terms of my portrayal of Zach I've certainly drawn on some of my own experience but I'm not basing him on anybody particularly. It's especially interesting playing him having been a judge on Over the Rainbow because I think in some ways A Chorus Line is a forefather of those casting shows. As an audience member you're seeing the audition process and sitting there with me wondering who you're going to hire. We're all armchair critics and that's why we're obsessed with TV talent shows.

There's of course an added poignancy that this is the first major production since Marvin Hamlisch's death last year. He was a hugely influential figure and what I love about his music is that he's so unfussy - A Chorus Line is a great example, in that there are no gimmicks or outlandish costumes. There's such a simplicity and directness to songs such as "What I Did for Love" that really showcases his genius. I wonder if we'll ever see the like of him again.

On marking 30 years in showbusiness

Looking back over the past 30 years, there have been so many highlights. I'll always have especially fond memories of Cats, which was my first major role and the only show my father ever saw me perform in before he died. I also loved The Drowsy Chaperone and Rent, which is the production I met my husband on.

But every job I do is a highlight because I'm so grateful to be working and to have the chance to keep developing. As long as I have the opportunity to do that I'll consider it all a highlight.

I'll be marking my 30 years in showbusiness in April with a show called Dames 'n' Dudes at the Hippodrome, which is something of a soundtrack to my life.

When I was a seven year-old boy I was dancing around the garden with a tea towel on my head singing "Wuthering Heights", I'd draw lipstick on and pretend to be David Bowie. Bless my parents for allowing me to do it and never telling me it was weird or wrong!

So I'll do everything in this show from Bowie and Bush to Sinatra and Streisand. It marks the first time I've got to be my own boss on a show and select my own material. Or, as my mother always said, "a little of what you fancy."

- John Partridge was speaking to Theo Bosanquet

A Chorus Line is currently booking at the Palladium until January 2014. Dames 'n' Dudes runs at the Hippodrome from 22-27 April