But, as Marti says, that's exactly when he knows he needs to dig in. He reckons that it's been the trigger to some of his best work.
It's what he felt at the prospect of starring in the hit musical Chicago with which he tours to Southampton's Ma
yflower Theatre from Tuesday February 16-Saturday February 27.
Marti recognised it as the very best reason to do the show – that and the fact that he fell in love with the sheer sensuality of the Kander and Ebb score.
"For me, the whole beauty of being an artist is to be able to diversify", says Marti known to millions for his work with the Scottish pop rock band Wet Wet Wet – and now gaining even more fans for his work in the musicals.
"You put yourself out there and you can be eclectic. What excites me is being part of a team. As a singer-songwriter, I do a lot of work with Chris Difford, and you have to know what you can and can't do. I love being part of a team.
"And I am lucky that I have got a fan base that comes on board when I do go off on tangents. They come with me and give me support, whether it is Broadway or Southampton or a snowy night in Glasgow – and that's just great. I am very lucky to have an audience that has the sophisticated tastes that allow me to do new things.
"It is great that they are excited by the choices that I make, like when I go away and do my interpretations of jazz songs, songs that are not part of the pop culture."
It's a freedom which is important to Marti – "having a enough rope to hang yourself!", he laughs. "But I don't go out there and think this is what I am known for. I am very proud of the work that I have done. Hindsight has a wonderful ring to it and you can always wish you did things differently, but the point is you make choices.
"As a child when you first have your dreams and aspirations to pick a career. When I was growing up and saying what I wanted to do, they'd say to you 'But we usually build ships around here - if you are actually lucky enough to have a job!'"
But Marti managed to live the dream, breaking through in a music industry which is very different to the one we know now: "The whole industry has changed dramatically in the last five to ten years. Every six months the industry changes. It's about how people access music, how people perceive the worth of music, whether they want to pay £8 to £10 for a CD when they can get it off the internet virtually for nothing."
Marti admits he doesn't have the answers – but it's certainly a case where the record industry has been caught with its pants down. Fortunately, though, the great live experience is stronger than ever – an area where music is experienced as it should be, Marti feels. In other words, as a community experience.
And much the same goes for the theatre where Marti continues to make the role of Billy Flynn in Chicago his very own.
Based on real life events back in the roaring 1920s, the show tells of nightclub singer Roxie Hart who shoots her lover and along with cell block rival, double-murderess Velma Kelly, fights to stay off death row with the help of smooth-talking lawyer, Billy Flynn.
As Marti suggests, Billy is probably a character we all understand better now than when he was first created.
"In the early 70s, it didn't really resonate as much as it did later, now that we are in a much more media savvy age, with people much more aware of manipulation. I don't know that people were more naïve back then, but people are a bit more cynical now when people are trying to sell themselves.
"He's a bullsh*t lawyer, and in the 21st century that doesn't really come as too much of a revelation to people. I have had a few of those in my time!"
Tickets for Southampton on 02380 711811.
