Thomas Fersen is receiving guests at home, in his spacious Parisian apartment, a stone's throw from the Eiffel Tower. We find him perched on a sofa, surrounded by piles of records, hats, photography books and assorted objects worthy of a modern-day curiosity cabinet. Fersen can pride himself on having just released Le Pavillon des fous, an album which ranks as one of the most surprising new musical offerings of the season.

Following two and a half years after Pièce montée des grands jours, his new opus is a darker, moodier, more serious work. "This time round," says Fersen, "there's no direct illustration of the lyrics in the arrangements. That was a bit of a comic device I used in the past. But the new album's still very picturesque." An understatement given its curious, and at times curiously disturbing, cast of characters! The first single release, J'ai pas la gale (the tale of a bizarre love affair between a loser and an ogress) has already received extensive airplay on French radio. And Fersen is now preparing for a new tour, which kicks off on 5 November. Several dates are already sold out, including his run at Le Bataclan, in Paris (29 November – 3 December).        

RFI Musique: How do you go about writing your songs? When you're working on an album do you do all the songwriting in one go or write your material as you go along?
Thomas Fersen: I accumulate things as I go. I've always got work in progress, songs that aren't quite finished but have a working base that I can add notes to as I go along. I've already got songs in stock that I'll use later – and that's the way I always work! The thing is, I'm never too presumptuous. I never know if what I'm working on will become a song or not. There are plenty of things I start that end up going nowhere.

I don't believe in holding a gun to my head and forcing myself to do an album. I can't work to order, whether it's for myself or other people, I just can't do it. So when I come up with an amusing idea, something that tickles me or I feel I really identify with, when I feel as if a part of my self is ready to slide off and slip into a song and I feel the urge to write, well, I just sit down and start work. I've spent the past two years now – and maybe a bit longer, in fact – working on bits and pieces about mad people, or mad people as I conceive of them in any case.

You've already peopled your songs with a few mad individuals in the past on songs like Bambi and Monsieur...
Sometimes what happens is I'll do a song and then afterwards I'll realise that there's more to it, that it's a theme I can get a lot more out of. Then again, sometimes I'll start work on a song and things don't work out the way I want them to. That happened on this album with Mon iguanadon, for instance. I started work on the song but things didn't go as planned. Why not? Because there was actually another song hidden within Mon iguanadon. I didn't want to turn round and throw away the lines I didn't need because I thought they were pretty good, so I turned the spare bits into another song, Hyacinthe.

There was another occasion when I'd come up with the idea for this total caricature of a family. I started out on what was going to be a lullaby, with the mother singing these things directly into the child's ear. And that's what gave the song so much mileage. I had this solid lullaby structure, this song that was soft, soothing and very easy to sing and memorise. And all of a sudden I remembered this holiday in the country when I was seven, eight or nine years old, I don't remember exactly. Anyway, I spent that holiday burying dead insects in matchboxes under a tree. I could picture the exact spot! I used to erect these little crosses over the graves and then twenty minutes later I'd dig everything up again to see what had happened to the insects. When I started writing the song I began with this story, but then I found it didn't fit with the idea I'd originally had in mind so I turned it into Cosmos instead. Maybe I'll resurrect my caricature of a family again some time in the future.

Could you ever imagine doing a good old concept album, like rock bands used to make in the 70s?
Well, the thing with me is I write my songs and then afterwards I see the concept! It's like the concept catches up with me as I go along and that's the way I prefer it. Working that way means there's some truth in what you're writing. You're not writing to order.

On the sleeve notes to Le Pavillon des fous you explain that the majority of the album was recorded at home...
I've always recorded the first drafts of my songs at home. It simply got to the point where I got a bit fed up with redoing things in the studio which I'd done perfectly well the first time at home. So this time round we only did certain things in the studio like bass, drums – and even then not all of them – and then there was the organ and the backing vocals… It's not because I'm a control freak or anything. I feel it's an absolute necessity to work that way. Ever since I started working on the arrangements for my album Qu4tre, I found it led me to get more involved with the production side of things. Working this way means that when I'm in the studio I can work exclusively on the production and not worry about my voice or anything.

So you recorded all your vocals at home this time round?
Yes, apart from the track Mon macabre. When I record the first draft of a song, when I sing it for the first time, there's this freshness and spontaneity about it that I lose afterwards and never find again until I do it live in concert. Between the two there's this lapse of time where I really miss the audience.

You're actually a talented multi-instrumentalist, aren't you?
No, not at all! OK sure, I like to try my hand at everything, but I could never be a session guitarist or pianist. I play different instruments for myself in secret when there's no-one else around and I'm just following the urge to create a new song. But apart from that ...

So by playing all these different instruments and recording at home and arranging your own albums, are you living out some fantasy of autarky?
I don't really have that fantasy any more, but I admit I did have a sort of Paul Léautaud fantasy for a while. I'd dream of just disappearing from the world and doing nothing but write. But the problem is, I'm deeply unhappy when I actually do that. I have this urge to go off and curl up in my lair. I'll suddenly take off and hide myself away in Brittany, here, or Montreal, wherever ...

The thing is, though, I'm not actually a solitary type at all. I'd like to be the kind of person who could feel fulfilled in their solitude, but that's just not the case. When I write I'm not alone, you see. I've got all these other people in my head. I'm constantly thinking of other people even when they're not there. The flat's completely silent, there's not one little sound, but you're all there with me. It's not like I'm on a desert island. I'd be the first person to go insane on a desert island, in fact!

Thomas Fersen Le Pavillon des fous (Tôt ou Tard/Warner) 2005

Tour dates: 5 Nov. - Noisiel, 9 Nov. - Nancy, 10 Nov. - Strasbourg, 17 Nov. - Brest, 18 & 19 Nov. - Rennes, 23 Nov. - Arras, 24 Nov. - Lille, 25 Nov. Brussels, 29 Nov. - 3 Dec. Le Bataclan (Paris)