Some 40 years after he became a heart-throb pop star, David Essex is still enjoying sell-out theatre tours and rock gigs. He reveals the secrets of his longevity, the importance of family in his ever-travelling life and how working with his much younger wife has been a success he hadn't envisaged, as his memoir, Over The Moon, is published.

By Hannah Stephenson.

For a guy who only ever wanted to be a jazz drummer, David Essex has done pretty well for himself.

From the sexy, blue-eyed pin-up who sang Rock On and Hold Me Close, to the star of stage and screen who played revolutionary Che Guevara in Evita and tortured Eddie Moon in EastEnders, his work has spanned generations of fans.

And he shows no signs of stopping. The 64-year-old singer-songwriter and actor, who starred in musicals Godspell, That'll Be The Day and Stardust, is as busy as he's ever been, spending little time at home in central London.

He's currently headlining in a theatre tour of All The Fun Of The Fair, a musical using songs from his own vast back catalogue; is completing Gajengi Boy, a film starring his son Billy, in which Essex has a cameo role; has a rock tour planned for November, and has just had his second memoir, Over The Moon, published. He's also hoping to squeeze in an album this year.

A grandfather of four, Essex reckons his longevity is down to the fact that his career has been so varied that he hasn't yet been pigeonholed.

"Moving from one medium to another is very fulfilling and keeps you fresh," he muses. "Maybe as I move around so much I'm not such an easy target to shoot down."

He says his mentor and early manager Derek Bowman, a theatre critic and showbiz writer, opened his eyes to the possibilities of theatre, which helped prevent him from being stuck in one medium.

"As a 14-year-old, I'd had a very blinkered attitude towards music. It had to be black and obscure otherwise I wouldn't listen to it. I was reluctant to acknowledge The Beatles and everything else that was going on at that time. But I got over that."

His recent five-month stint as EastEnders' Eddie Moon was a complete contrast to anything else he'd done.

"It's fast and furious and I had a lot of big storylines and line-learning, thinking on my feet. If you can do something like that, you can do anything in acting terms."

His character wasn't killed off so he may make a return at some point. "I never shut the door on things. It's more to do with time because it does take over your life."

Over the years, he may have gained a laid-back image with his laconic speech and relaxed body language, but Essex is nobody's fool.

He turns down a lot of offers and wouldn't dream of appearing in any reality shows, a genre he regards as 'b*******'.

"The word 'celebrity' has been so devalued. If anyone calls me a celebrity, I wouldn't be that happy. There are people who are stars and then there's somebody who was known for being in Big Brother and then does a panto. There's a difference."

He's always been drawn towards projects that allow artistic freedom. In fact, 'freedom' is a word he uses a lot, which perhaps is a legacy from his mum's gypsy lineage.

The son of an East End docker, Essex had his heart set on a career in football with his beloved West Ham until he discovered music and formed his first band, the Everons, before hitting the big time in the stage musical Godspell and then as a solo artist, becoming every teenage girl's pin-up.

While some of his pop star contemporaries were getting high or hammered, and descending into drug and alcohol addiction, Essex kept his distance.

In his early twenties he was already married to his childhood sweetheart Maureen Neal and had two children, Verity and Dan, which went some way to instilling in him a sense of responsibility.

"I wanted them to respect me, not read about me lying in a gutter somewhere," he reflects. "I always like to know what I'm doing at any given time. I've never really been a drinker and I didn't do drugs."

His career rumbled along, but after the sudden death of his father Albert from a heart attack in 1994 and the death of Bowman a year later, Essex decided to take a break.

"Subconsciously I felt I'd done everything, had number ones worldwide, theatre shows, films, TV and sell-out concerts. I thought maybe enough was enough."

By then, he was with his second wife, singer Carlotta Christy, and their twins Bill and Kit, and he didn't want to make the same mistakes as he had with his first wife, when he spent so much time on the road.

"I regret not spending as much time with the first two children, but I was on a roller coaster with my career. My life had been taken over by work and being away."

By the mid-Nineties Radio 1 wasn't playing his songs any more. "Status Quo and Cliff Richard have made a big fuss about being ignored by Radio 1 and I see their point but it's not something I have a chip on my shoulder about. It is just the way things are.

"But after taking a break, I got a resurgence of energy and interest. I've always been a bit of a jobbing pop star. Maybe I just needed to step back for a while."

Today, he's more selective about work and doesn't want to repeat the frantic pace of life he experienced in the Seventies and Eighties. Family is all important and these days he has them all around. His daughter Verity and his daughter-in-law are his personal assistants.

After splitting with Christy, in 2010 he married his third wife, Susan Hallam-Wright, a Welsh actress 26 years his junior and co-star on All The Fun Of The Fair. She plays his prospective daughter-in-law on the show.

"Married life is good," he enthuses. "She's a good friend as well as a lovely person. Working together might have been awful but it's actually brilliant.

"I did have this little question mark about spending 24 hours together - and being an only child I'm used to a bit of space. But it's worked out fine."

The age difference has never worried him, even though Susan's the same age as his daughter Verity.

"I'm still about 23 in my head," he says. "To be honest, Susan's steadier and wiser than I am. I don't know if we'll have kids. We're both working hard at the moment so we'll just wait and see what tomorrow brings."

There's talk about a film adaptation of All The Fun Of The Fair, plus he's writing Che, a musical based around the life of Che Guevara, and a one-person play called Tramp. But he's always on the lookout for new projects.

"I'm not as impatient as I used to be because there aren't so many tomorrows left now. Maybe I'm a little bit more mellow but I still have an insatiable appetite for moving on. I'm a restless soul."

:: Note to editors: Please note language in par 13 :: Over The Moon by David Essex is published by Virgin, priced £18.99. Available now