"It's always played a large part in what I do," says Steven Severin on the phone from his home in Edinburgh. Best known as the bassist and equal creative partner in Siouxsie And The Banshees, Severin has spent the last decade or so focusing on soundtrack work for film and theatre. "I remember seeing the cover of the Pink Floyd album More. I never saw the film - I still haven't seen the film - but it was only their third album and I thought, Wow, that's what I'd love to do! Be in a band and be in a band that did soundtracks. One of the things that spurred me on was in the late '70s there were screenings of Kenneth Anger's Magick Lantern Cycle, at the old Scala. And I don't know what went on but at least one of them had a soundtrack by ELO. I thought this can't be right. If they've done it, surely it deserves to get something better? And obviously all of Kenneth Anger's movies have specially commissioned music anyway, that fits perfectly, so why would you bother changing that? And then I saw Philip Glass do Cocteau's Beauty And The Beast live, and a pretty rare performance of Todd Browning's The Unknown with music by John Cale, which was pretty staggering. So it's something I've wanted to do for a very long time."

Although birthed from the very heart of London's punk scene, the Banshees' musical background took in soul, psychedelia and, perhaps most importantly, the art-glam of David Bowie, Roxy Music and The Velvet Underground: acts that placed an equal emphasis on visual presentation and made explicit reference to the artistic, theatrical and cinematic avant-garde. The early Banshees records too contained myriad references to film, their name derived from the 1970 Vincent Price chiller Cry Of The Banshee. The band's later albums took on an increasingly cinematic sweep, and they scored a 1992 hit with the single ‘Face To Face', taken from the soundtrack to Tim Burton's Batman Returns. So it's not surprising that Severin has continued to pursue this direction since the Banshees broke up in 1996, beginning with 1998's Visions album, a reworked and extended version of his soundtrack to Nigel Wingrove's controversial short film Visions Of Ecstasy.

Following that with the Maldoror album, which began life as a musical commission for Brazilian theatre company Os Saturos' production of the Comte de Lautréamont's poetic novel Les Chants de Maldoror, Severin was then asked to provide music for The Woman In The Dunes, a stage production by the dancer Shakti. He worked with Shakti again on Beauty And The Beast, a 2005 collaboration with his wife Arban and the first release on their Subconscious Music record label. The following year he and Arban scored Paul Burrows' psychological thriller Nature Morte, going on to work with director Matthew Mishory on his acclaimed short Delphinium: A Childhood Portrait Of Derek Jarman (2009) and the forthcoming feature Joshua Tree, 1951: A Portrait Of James Dean. Severin is now about to embark on the second leg of a UK tour performing a bespoke electronic soundtrack for Carl Dreyer's 1932 surrealist horror Vampyr, the Danish director's follow-up to his masterpiece The Passion Of Joan Of Arc. Vampyr was actually Dreyer's first sound film, though it retains the aesthetic of a silent picture and uses dialogue sparingly. It is the third in Severin's Music For Silents project, following an initial outing that featured Germaine Dulac's 30-minute classic The Seashell And The Clergyman (1928) alongside a selection of contemporary silent shorts, and a tour soundtracking Jean Cocteau's The Blood Of A Poet (1932).

What are your criteria for selecting films to soundtrack?

Steven Severin: Well, there's a fairly limited supply to start with. And then you whittle down all the ones that have been done to death, like Metropolis and Nosferatu, and I just choose ones from the remainder. And once I began doing this they kind of picked themselves. I really liked doing The Seashell And The Clergyman. It had practically no narrative to it, it's one of the very first surrealist films ever made. Following that, once I looked again at The Blood Of A Poet, it became obvious that that would make a good sequel. And then when I looked at Vampyr I started to see connections between all three. There's a single male protagonist in all three movies, it's in a world that is not quite making sense, and you cannot control it in any way, shape or form. They're at the whim of events. That made a nice little trilogy for me.

Is that a self-contained trilogy now, or is will you be seeking out other films that continue the same themes?

SS: It feels like a place to stop and take stock. Once I've played out this tour and released the CD, then I'll maybe take a break from it and think about what comes next. It may well be an extension of the trilogy, or I may go off in another direction. I haven't quite made up my mind yet.

One of the many interesting things about Vampyr is that the main actor, Nicolas de Gunzburg, who appears in the film under the name Julian West, went on to become an important figure in the New York fashion world, and had a whole other life after that.

SS: Well again, that's a connection with The Blood Of A Poet, because that was financed by the same sort of aristocracy that financed Un Chien Andalou as well. So there seemed to be a little trend in the late '20s, early '30s of these kind of independently backed, arty films, that all came together. Maybe they influenced each other, who knows? It's highly likely that Dreyer would have seen these films.

Not only were they independent films but, as you said before, they had very unusual, almost non-narrative structures. They were still at that point in the early days of cinema when they were able to feel their way and experiment naturally, because the grammar of the form hadn't been set in stone yet.

SS: Yeah, exactly. Plus there's also the dimension of they're just trying to get to grips with how to utilise sound properly. The aesthetic of Vampyr is very much a silent one: the close-ups, the blank expressions, even the use of intertitles. There's a lot of reading from a book and very little dialogue. So it became straightforward to take off all the dialogue completely and just use the subtitles.

Apparently Dreyer based certain scenes on particular paintings, not just from the surrealist school but classic paintings. This is obviously an area of interest for you too, art and surrealist art in particular.

SS: Yeah. Just before you called I was reading something where he showed one of the leading actresses reproductions of some of Goya's paintings while they were shooting. It didn't say which ones, but obviously that had... I mean, what other influences could they have at that time really? There was no rock 'n' roll!

Good point. So how do you go about creating a score? What's your starting point with a film like this?

SS: Initially it's a lot of watching, re-watching and researching, until I start to know the film back to front. And then the actual writing of the music is really quite fast. I just pick one scene that I'm instantly attracted to in terms of music and start from there. It's a bit like a jigsaw. You just fill in the gaps and think, Oh, that piece could work there as well, slightly adapted. You get a feel for the pacing as you go along. And that's the other thing with the three films I've chosen: I'm sort of working my way up in terms of time. When I first thought of the idea I was a bit daunted by doing 90 minutes straight off. How I could keep the audience enthralled for 90 minutes? So I started with much shorter films and worked my way up. And even Vampyr is just 72 minutes long. It's not like a modern day feature.

You said about doing a lot of research: do you reference much outside of the film?

SS: I just read a lot of the critiques of it and anything that spins off from that, really. Vampyr is loosely based on Sheridan Le Fanu's short story Carmilla, so I read that. All of these things... Now that you have the internet you can just keep going and going and going!

The trouble is knowing when to stop and get down to work, I suppose.

SS: Exactly. When you have something this old, many people have approached it to try and figure out what is going on. There are a lot of questions left unanswered in the movie.

When you play it live, does your performance change from night to night much?

SS: Not that much. I run everything off Ableton Live and I mix it as I go along, and introduce different layers and elements. But the core of it stays pretty much the same, because I'm not an improviser. I've sat there and decided what I want where and why I want it, so I keep it pretty much the same every night. But I've got a few devotees who come along to several screenings, and they all hear and see different things in it every night. So it's something that repays second and third viewings, and hopefully listenings.

Have you had any adverse reactions to performing a predominantly electronic score as opposed to a piano or orchestral one?

SS: Oh yeah. There was a lot of initial resistance from the people at Eureka, because they'd spent a lot of time and money restoring the sound on the film, which is basically the music, but there is a little bit of dialogue. And they were a bit baffled as to how I was going to change it into a silent film when it's a sound film. I didn't see anything, but apparently on their forum there were people outraged. But they don't own the film; they own the restoration. So I felt I'm entirely justified in doing what I did. Some people - very few actually - questioned whether it's an actual performance or not, because it's basically coming off a laptop, but I deliberately enter the cinema once the house lights have gone down, and sit in the dark so that my physical presence doesn't take away from watching the movie and listening to the music. I'm not quite sure what people would be expecting me to do in terms of a song and dance or whatever! The way I've done it is exactly the way I wanted to present it. If people have a problem with that I'm sorry, but they can go and watch something else.

In 1989 you recorded a score for Nigel Wingrove's short film Visions Of Ecstasy, which was the only film banned in Britain for blasphemy. It was finally passed by the BBFC in January this year, following the abolition of the blasphemy laws in 2008. How did you became involved with that project?

SS: I don't quite remember, but Nigel insists that he interviewed me in Plymouth in 1977 or something, for his fanzine. And I half recognised him when I met him in a Soho nightclub called Fred's in the late '80s. He was chatting away and said he was just about to start doing this short film, and would I be interested in doing the score? And I immediately said yes, and it all went ahead, and it was a complete bombshell that it got such an adverse reaction from the video censors commission, or whatever it was called, the board. I don't think I learnt too much about scoring films, because it was only 18 minutes long, and it was all pretty much done in a couple of days. But what was really enlightening was the court case that followed. It all took place in an institute of hygiene, somewhere in Portland Place [the Royal Institute Of Public Health]. On one side you had Derek Jarman, Marina Warner, Colin MacCabe, all standing up [for Wingrove], not particularly in support of the artistic merit of the film, but just the idea that it shouldn't be censored on the grounds of blasphemy. And it wasn't that the censors found the film blasphemous, it was the fact that they thought they could be prosecuted for blasphemy. That was their remit from the director of public prosecutions; that they couldn't give any certificate to anything they thought might incur some sort of private lawsuit.

Of course this was at the height of the Satanic Verses and The Last Temptation Of Christ scandals and brouhaha, and they basically picked on this little English first-time director, with no studio behind him, and they thought they could just swat him away. But of course he fought on to take it to Strasbourg and The Hague, and inadvertently that springboarded my solo career. He was convinced that he was going to get the ban overturned when he went to the Court Of Human Rights, and he said why don't you make a whole album to go with the release of the movie? Of course I went ahead and did the whole album, only for the film to have its ban continued! And it left me with an album that no major company wanted to touch, because there was no film to hang it on. So inadvertently I got a solo career out of it, plus started my own label through the internet, but none of that would have happened without Visions Of Ecstasy.

I understand that Nigel is fairly ambivalent now about whether he does actually want to release the film or not.

SS: No, no. He's changed his mind. It's being released [Visions Of Ecstasy was issued by the Redemption/Salvation label earlier this month]. A couple of weeks ago he sent me the draft of a little booklet he's written about the whole affair, and it makes for a very interesting read. So he's finally relented. I think you're right, he was ambivalent for a couple of years after [the film's completion], because it really affected his life. He lost his house and everything, you know. But I think he feels it's a chapter that needs to be closed.

So that led into your solo career, which has been pretty much soundtrack work or theatrical scores. Since you set up your second label, Subconscious Music, you've produced a lot of collaborations with your wife, Arban. Tell me about your working methods.

SS: We never sit down and write music together. We do it in tandem. I may start something, then Arban will work on it, then I'll come back and do more. We just perfect it until we're both happy. It's a pretty organic process and it means, particularly when we're working on a film, that there's somebody working on it almost 24 hours a day. It's very intense. And that's the way it seems to work for us. Neither of us works well collaborating there and then, we both need our space to add and subtract from what's already there. But it just happened naturally, so that's the way we do it.

I suppose on the one hand soundtrack work must involve a lot more freedom than working as part of a rock band, but also a lot more discipline at the same time.

SS: Yeah, it has both. For the most part, people don't come to me expecting something I wouldn't do. They choose me for a reason. I've had varying degrees of success with these things. Some people leave you totally alone, and everything you do they say is great and works perfectly, but that's kind of rare. More often than not, you do something and people just want it altered slightly, or when it gets down to the dreaded editor it gets chopped and changed. We both work to this idea that what we do is a lot more immersive than a lot of film composers. It's not like we just make up themes and give them those; we actually work almost frame by frame with the film. Part of what we do is a bit like sound design. So when editors start to mess with the exact placement of where you've put something, that drives you mad. But it's a small price to pay for having so much fluidity with the rest of the work.

And is this where you see your musical future continuing? At least working from some form of visual inspiration?

SS: Yeah. I can't envision myself going back to songs, going back to a band or anything like that. I think that part of my life is gone. The Banshees did a reunion tour - it must be ten years ago now - and it only served to prove the point that we shouldn't be doing it! In my mind nobody over 40 should even attempt to be in a rock band. It's the province of a younger enthusiasm and more of a senseless engagement.

Most reunions are only really undertaken for financial reasons, I should think.

SS: Yeah... Well, if I'm being charitable a lot of people would say that they had unfinished business, meaning that they felt the lifespan of the band was cut short for one reason or another. It's different with the Banshees. We had a long, long career - a continuous flow - so there's nothing left to say. The whole point of doing the reunion tour was to see if we did possibly have anything more to say. There was talk of if the tour went well then maybe we could go into the studio and write a new album. But of course that never happened, because things have moved on and people have changed. And the same chemistry definitely wasn't there anymore.

Steven Severin's Vampyr tour continues from May 8 to July 5; a full list of UK dates can be found here. Be sure to check his website for more information on this and future projects.