STANDING on stage during the opening night of Hair in West End in 1968, a young and excited Elaine Paige had no idea what was ahead for her.

The musical became a box-office sensation and since that opening night, Elaine has been treading the hallowed boards of theatre and concert stages in some of the most powerful female roles of our time.

Elaine has had starring roles in the hit musicals Evita, Cats, Piaf' Grease, Jesus Christ Superstar and Chess, which was written especially for her. Not to forget Billy, Anything Goes, Sunset Boulevard, both in West End and on Broadway, The King and I, The Drowsy Chaperone' Sweeney Todd' in New York, and many other shows.

It has been an amazing journey and Elaine says she cannot believe it is 40 years since it all began. "I never expected it. I don't think I thought that far ahead," she laughs warmly. "It's fantastic to still be doing what I do and what I love, 40 years on."

This will be Elaine's first appearance at the Llangollen International Eisteddfod and she is really looking forward to it. "It's great to be part of this festival that has been around for more than 60 years. It's amazing, a great thrill."

Elaine is no stranger to Wales, saying: "I love coming to Wales. I used to come to Wales as a child on holidays." She has also performed at Bryn Terfel's Faenol Festival.

Accompanied by an orchestra of London musicians, the concert at Llangollen will encompass Elaine's wide-ranging and astonishing performing talents and will feature favourites from her many roles over the decades, as well as Elaine sharing a little about her life.

It is the first show in what will be an extensive world tour for Elaine, celebrating the 40th anniversary of her debut on the West End stage. Over the next year or so, Elaine will be performing in Sweden, Denmark, Norway, Ireland and China, as well as the London Palladium in November. After a little time off for Christmas, Elaine will be touring the UK.

"It's not exactly my farewell tour but if I survive, which I shall, I will need a break," jokes Elaine.

As a singer, Elaine has had hit songs including Don't Cry for Me Argentina from Evita, Memory from Cats and I Know Him So Well, a duet with Barbara Dickson from Chess. She is also a producer, author and broadcaster but admits: "I have always thought of myself as an actress first, who sings, but the fact is, the main part of my career has been involved in musical theatre.

"Music has played a huge part in my life," says Elaine, adding she always approaches her music as an actor. It is about communication and lyrics, she says. "I am telling a story, that's what's important, as an actor."

As for her favourite role, Elaine says: "That's always a very difficult question because whatever you are doing at that time, that's the one.

"I have been very, very fortunate in this long career. I have played some wonderful parts and Evita will always be very special for me. I first performed it 30 years ago. It changed everything for me, gave me a career and was a wonderful role to delve into.

"I had to research and find out all about Eva Peron. No one in the world knew much about her or the Perons or the political situation in Argentina until this musical. It was something meaty to get hold of. It had a wonderful score, brilliant lyrics and was a glamorous from rags to riches story. I adored to play it."

The role of Edith Piaf was very special to Elaine as she had always admired Piaf as a singer. It was another meaty rags to riches story, she says, based on a real woman, and appealed to her.

Each show lasted three hours and forty minutes and included 15 songs.

Elaine says it was like doing Hamlet every night. "It was a great physical and emotional undertaking. It was fantastic and fulfilling to have done that and was something I really, really did enjoy."

The role of Norma Desmond in Sunset Boulevard, of an older, fading woman was also a favourite. "It's a tragic story and she shows great determination, drive and fire but she is a really sad and vulnerable person," says Elaine.

"Playing some of these real meaty roles are what I have enjoyed playing the most."

She says: "Chess was very special to me. It was written with me in mind." It was totally original and gave Elaine a number one single in the pop charts which she was thrilled about.

In September, Elaine's autobiography Memories will be released. She is busy working on it at the moment. "It has been fun looking back over my career. I had to dig out all the books my parents kept to kick-start my memory." It has taken her a lot of time but she will be thrilled when it's done and she can see the outcome.

When she is not working, Elaine is kept busy playing tennis, clay pigeon shooting for charity, entertaining, seeing friends and leading a more normal life. "I love going out to dinner and I love going to the theatre myself. I have a love of the arts and I do all I can. That's what my life is – art galleries, theatre, concerts."

Is she a glass half-full or glass half-empty person? "Definitely half-full, absolutely. There's not much room in the glass to fill it up! I am very lucky," says Elaine enthusiastically.

Each week she has her own radio show on Radio Two, which she is enjoying as she gets to be on the other side of the microphone and interviews many interesting people.

Elaine's fans span the globe, from the UK to China to the US to New Zealand. She says: "I want to thank everybody for sticking around with me for 40 years. It's really amazing. Without them, I would not have had a career, so I have been very blessed in many ways, not least by their staunch and loyal support."

The first lady of British musical theatre remains inspiring and positive and after 40 years of entertaining people around the world, she shows no sign of being jaded.

"I am just keeping on keeping on," laughs Elaine. "My career has been very diverse really. Much more than I could ever have imagined."

Would Elaine Paige do it all over again if she had the chance? Without a moment's hesitation, she replies: "Absolutely!"