Your latest album has gone down a treat with the critics, but to Belfast audiences you’re probably still best known for collaborating with Snow Patrol on their track Set The Fire To The Third Bar. How did that come about?

Well, Gary Lightbody wrote the track with me in mind, he imagined my voice singing it, and he got a message through to me to that effect. We had not met then. Obviously, I was very flattered and really excited. I didn’t know their music that well, at that point, but I really liked the song.

They were in Dublin putting the finishing touches on their album, and I had a gig around the corner in Temple Bar, so we were able to arrange to meet up in the studio and do the track. After them I duetted with them live on stage a bunch of times, like at the V Festival and lollapalooza.

I liked them right away, they are such lovely guys. I think the fact that Gary wrote a song with me in mind probably says more about him than me — it’s very typical of him, he is such an endearing, generous kind of person.

You’re sometimes referred to as a ‘folk’ artist, but on the evidence of your own recordings, I would say you are not remotely folk. You can be quite rocky and raunchy, kind of like Marianne Faithful crossed with Maria McKee. How would you describe your music?

That’s a tough one. If I’m travelling through an airport, like at passport control, and I’m asked what I do, I usually say a folk singer, ‘cause I can mimic picking a guitar without any foreign language ... I suppose people think of me as folkie because that’s where I started out, that’s where I came from [Wainwright’s mother Kate McGarrigle has been a legend in Canadian/American folk circles since the Sixties]. When people see a woman on a stage, alone with a guitar, they think ‘folk’.

But to be honest with you, I don’t really mind the label; the only thing is, it might mislead people, and if they came to see me live, they might be disappointed. In some ways, I would love to be worthy of the label ‘folk artist’; I am truly an example of the modern singer-songwriter who’s self-obsessed, whereas that would not be the original nature of folk music.

Yes, your music does kind of fit into that New York ‘neurotic’ aesthetic! You write about yourself a lot ... do you ever get tired of analysing your emotions?

Yes, as I get older, I get tired of talking about myself. Now, I’m more interested in seeing if I can use my music to bring about any political, or environmental changes. I’m wondering is it time for a new form of protest song.

I’ve just returned from a fact-finding, environmental mission to Greenland. The whole project is called Cape Farewell and loads of artists were involved in this year’s trip, including Jarvis Cocker, KT Tunstall, Laurie Anderson, Shlomo — loads of singers, writers, professional people, just a whole mix. I was so impressed by Jarvis Cocker, he’s so intelligent and I really love his take on things, and the way he just does his own thing, regardless of what anyone thinks.

On the trip, we were all thinking about the way in which language is used — you know, like so many of the words we use in terms of culture, for example ‘creative’, get hijacked by people who want to sell you something. It makes you think about changing your lifestyle rather than buying a lifestyle, or selling a lifestyle. Interesting.

I suppose you could call Bloody Mother F**king A**hole — writ

ten about your relationship with your father, Loudon Wainwright III — a protest song of a different order!

Yes, you could, although it doesn’t mean the same thing to everyone. I think it’s a very good song but it sort of took on a life of its own, but that’s fine with me. I’m very happy that people liked it. I’d rather be known for a good song like that, than a really crappy hit, even if BMFA never got me much airplay.

But you actually get on ok with your dad now [Martha was raised by her mum in Canada after her parents broke up]? You’ve toured with him, and appeared on his live album from 2003, So Damn Happy.

Yes, we get on fine!

It’s hard to see your name without your famous, musical family being mentioned — your father Loudon, your mother Kate, your brother Rufus. As an emerging artist over the past decade, did you feel in their shadow?

I had frustration towards them for a long time, as I wanted to be heard on my own terms. When I was growing up, I was only really interested in their music projects if I was involved! But once I started getting heard by myself, as a solo artist, I mellowed a lot, and a sense of normalcy set in.

And we’re all close. Rufus and I are kind of part of this New York set, which includes Joan Wasser and Antony Hegarty. We’re all good friends. Rufus was always going to grab the limelight as he’s a pzazz kind of performer, but that’s ok.

You recently got married. Your husband, Brad Albetta, is also your producer, and plays in your band ... is it quite intense working together and hanging out all the time, especially when you’re on tour?

Can you hear him snoring? He’s with me right now, catching up on some sleep!

No, it’s great to have him on stage with me, as opposed to somewhere out in the audience. It means I get to share what is probably a really great time in my life with him.

I think for a long time I yearned for someone outside of my family to love and help me. I felt the need to not always be searching and needing. So yes, I’m a lot more content.

So, given that you are happily married, where did the angsty title of your recent album come from: I Know You’re Married But I’ve Got Feelings Too?

Well, that was about a couple of people from the past, you know when you have people you still have obsessive feelings for? When something’s still there, even if it’s ten years later? I was haunted by some of that and writing and singing about it has helped me work through a lot of that.

You realise that obsessing over someone says more about you than it does about the love-object.

This tour is a biggie, it has taken you all round Europe. What are your plans after that?

I’m performing in the ‘sung ballet’ Seven Deadly Sins, by Kurt Weill and Bertolt Brecht.

It’s a Royal Ballet production, and it will be at Covent Garden in the New Year, so that’s pretty exciting. I’m looking forward to it.

Martha Wainwright plays the Grand Opera House on October 31. Box office 9024 1919 or www.goh.co.uk