WHEN Mark McMullan walked on stage for his Britain’s Got Talent audition, he thought he’d made a terrible mistake.

A family tragedy meant he’d given up his dream of singing to train as an architect, and when the BGT opportunity arose he wasn’t sure it was for him. He needn’t have worried. Mark floored judges Simon Cowell, Amanda Holden, David Walliams and Alesha Dixon with his moving performance of Les Miserables show-stopper Bring Him Home, dedicated to his brother, and reached the final of last year’s series. He lost out to Chelsea Pensioner Colin Thackery, but Mark was snapped up by musical theatre producers who, like us, had fallen for his incredible voice.

Now Mark, 24, stars in family favourite Joseph and the Amazing Technicolor Dreamcoat in his first major musical role.

Growing up in a musical family in County Down, Northern Ireland, Mark started singing aged four. “Everyone played instruments in our family and my grandad sang in a choir. When I started singing he took me under his wing. I’ve never had formal training, I learned it all from him,” says Mark.

The family’s life changed forever when Mark’s brother Declan suffered a cardiac arrest, aged just 19, resulting in brain damage. Declan now has the devastating condition Locked-in Syndrome.

Mark often played Bring Him Home at Declan’s hospital bedside. “When I was 14 I was in a junior show of Les Mis, I loved that song but had no real meaning behind singing it. When Declan took sick, it took on a new poignancy,” says Mark. “I couldn’t express, verbally, how I felt about what happened to Declan at that time, but when I sang Bring Him Home I could express it without saying it. It’s a song that means a lot to our family.”

Mark was 17 when his brother nearly died, and he decided to abandon his dream of being a singer. “I felt it was important to have a career so I could help support my family, so I studied architecture. I was starting to think music wasn’t to be and was ready to give it up when Britain’s Got Talent came along. I guess it was the universe telling me I was wrong,” he smiles.

It was a video of him singing to Declan went viral that led to Mark performing Bring Him home on an Irish TV show, then came the BGT audition. His life has been a whirlwind ever since. He’s loving the title role of Joseph in Tim Rice and Andrew Lloyd Webber’s much-loved Biblical musical. “I was in an amateur production when I was 12, playing one of the brothers and the Pharoah. I’ve grown up with this show, subliminally I knew all the songs,” he says.

Re-telling the story of Joseph, his 11 brothers and that coat of many colours, the show is packed with familiar songs, including Any Dream Will Do, Go Go Go Joseph and, Mark’s favourite, Close Every Door To Me. “It’s Joseph’s biggest solo and I like acting emotional songs,” he says. “I’ve had more tragedy than good in my life so when I bring emotion to a song I can unlock the performance a wee bit.

“It’s a great family show. We get generations coming; people who were kids in the choir 40 years ago, and now their own kids are in the choir.”

Mark’s biggest fan is Declan, who was at the opening night of the UK tour. “I’m lucky to have a large family, there’s someone at just about every theatre on tour. That pushes me to do my best performance,” says Mark.

For someone whose life has changed enormously in a year, he’s remarkably level-headed. “When I did BGT I thought ‘This could be my first and last time at this, I have to make the moment count’. I’m still doing that,” he says. “I don’t expect anything from that show, whatever happens is a bonus. Now, I love it so much it doesn’t feel like work. If I can’t find fun in my job, it’s not for me. The key to this show is if we’re enjoying it, the audience is too.”

* Joseph and the Amazing Technicolor Dreamcoat is at the Alhambra, February 4-8. Call (01274) 432000.

Emma Clayton