Zoe Tyler has spent much of her television career on the judging panels of shows searching for the next big talent.

She was a judge and vocal coach on BBC1’s How Do You Solve A Problem Like Maria? and Any Dream Will Do, Andrew Lloyd Webber’s televised search for stars for his revivals of The Sound Of Music and Joseph And The Amazing Technicolor Dreamcoat.

She also coached youngsters on TV shows Hairspray: The School Musical and My Camp Rock.

But what you may not know about Zoe is that she started her career performing in West End musicals and is an accomplished singer.

Now she’s returned to the stage, playing Eva Cassidy in a show about the late singer’s life.

Eva was a little-known singer in her native Washington until her death from skin cancer, aged 33. After her death, her haunting interpretation of Somewhere Over The Rainbow caught the attention of Terry Wogan, who championed it all the way to No 1. Her album, Imagine, also topped the charts, beating Robbie Williams and Beyonce.

Zoe plays Eva from the age of 14 to her death. “It’s a musical play, featuring 21 of her songs,” says Zoe. “I’m a massive fan. I’ve been singing Over The Rainbow for years and I sing Songbird at weddings and funerals, so I’m thrilled to play Eva. It’s emotionally draining – the last 20 minutes is quite traumatic – but I’m happy to be singing again. I’d taken time out to have my son and this was an opportunity to get back out there. People say, ‘Ooh, I didn’t know you could sing!’ I did 15 years of musical theatre.”

Zoe, 37, has studied footage of Eva. “She was so diverse, vocally; she sang rock, country, soul and gospel. As a vocal coach I find that intriguing,” she says. “She didn’t fit into any niche and she didn’t care about image.”

Zoe is joined on stage by Scottish singer, and winner of Channel 4’s Musicality, Donna Hazelton, and Holby City and Casualty actor David Paisley. “The play goes from Eva’s life with her musical family – they were like the Von Trapps – to her studio work with her boyfriend and mentor, Chris Biondo, and their live recording of Blues Alley,” says Zoe. “Her appeal is the purity of her voice. People listen to her when they want to chill.”

Zoe joined Les Miserables at the age of 20 and went on to star in a range of musicals, from Jesus Christ Superstar to Fame. As a backing singer, she has worked with artists such as Elton John, Rod Stewart, Will Young, Cliff Richard and Donna Summer.

Now she’s well known as one of ITV’s Loose Women. “I love it,” she smiles. “We put the world to rights and moan about men. Perfect!”

Over The Rainbow: The Eva Cassidy Story is on at St George’s Hall on Saturday. For tickets ring (01274) 432000.