Perhaps that should be ‘key to his piano’?
The singer, who found fame and fortune with 90s popstars a1, says he is much happier sitting behind a piano.
“I’ve always played the piano, ever since I was three years old and I have always loved it,” says the 30-year-old.
“I have always felt more confident sitting behind it than performing on stage, to be honest.”
That’s not to say he doesn’t love performing, of course, as his enduring connection with a1, and his more recent roles in the theatre, prove.
Now he’s thrilled to be back in Glasgow, with the show Piano Legends, later this month.
“The Glasgow audiences were always the best when we toured with A1,” he recalls with a laugh.
“Always the loudest! I’m really looking forward to being back in the city, and at a venue I’ve never performed in before. I have a feeling the concert hall will be a bit different from the Armadillo. It’s perfect for this show, which is all about the great piano songs and singers of recent decades.”
Piano Legends, a celebration of Elton John, Carole King, Billy Joel and the like, comes to Glasgow Royal Concert Hall on December 28.
It’s a big, bold concert with extra bits and pieces into the bargain, including stunning choreography, a powerhouse live orchestra, and extra vocal performances from west end stars Carole Sennett and Miranda Wilford.
“We’ve packed loads in, it will be a great show,” says Mark.
“These are the songs I grew up listening to, the stars I loved. But there are also a few newer tunes, from people like Lady Gaga and Alicia Keys.
“And everyone will recognise the tunes, like Hey Jude; Just the way it is; Bohemian Rhapsody and more.”
Mark is fronting the concert fresh from a tour of A Spoonful of Sherman, a musical all about the famous Sherman brothers, the American songwriting duo responsible for the scores for Mary Poppins, Chitty Chitty Bang Bang and more.
The 32-year-old is probably best known, however, as one quarter of 90s boy band A1, who had two UK number 1 singles and eight Top Ten hits, five studio albums and countless awards, including the Brit Award for Best Newcomer.
The foursome – Mark, Paul Marazzi, Christian Ingebrigtsen and Ben Adams split in 2002, and seven years later, reformed as a threesome without Marazzi.
Now the four are back together, performing in a 20th anniversary tour which has taken them all over the world.
Mark explains: “It’s incredible – we have just come back from Asia, and we had a great response. We’re delighted people still want to come and see us.
“It’s great we are a foursome again too – that’s something I thought might never happen. We’re all in a good place now – Paul is a dad, with two kids, so he is the only one of us who has actually grown up. The rest of us are still acting like kids!”
Mark grew up in a musical household – his dad was in a rock ‘n’ roll band, his mum played piano and drums.
“My grandad was musical too, so I was just surrounded by it,” says Mark.
“I was never pushed into it, thought, I was just lucky to have lots of opportunities, and I’ve made the most of them.”
He grins: “I love being surrounded by music in all of its forms!”
Mark has penned songs for a number of international artistes, including Michael Bolton, Boyzone, John Barrowman and Charlotte Church, and has starred on stage in Guys and Dolls, Cinderella and Seasons of Love. Recently, he joined former Strictly Come Dancing professional dancer Kristina Rihanoff for her Audience With… tour of the UK.
One of his favourite moments in recent years, however, was getting a call from the people behind the Harry Potter movie soundtracks.
“They asked me if I wanted to sing with Jarvis Cocker in the next Harry Potter film,” he smiles. “I didn’t have to think about it! I was made up to be part of it – it was incredible.”
Mark will enjoy a “big family Christmas” at home in London before he heads north for the Glasgow gig.
“I can’t wait to bring Piano Legends to Glasgow – hopefully it will get everyone in the mood for new year,” he says, adding with a frown: “I’m just gutted I have to be back in London the next day, and I can’t stay for a traditional Glasgow Hogmanay…..that would have been great…”
Piano Legends is on December 28 at 7.30pm in Glasgow Royal Concert Hall. Call 0141 353 8000 or visit www.raymondgubbay.co.uk for more information.