The sky over Notting Hill is so dark and oppressive that, for a moment, it feels as if it’s actually going to drop and hit the Portobello Road to smash the market stalls that are billowing in the howling wind. Up and down the street trash and other detritus is blowing wildly to create the impression of dancing garbage. This feels less like west London and more like some kind of vision of hell where the only concession to colour are the differing shades of grey that trickle down from the clouds overhead to grimy pavement below hurried feet.

In some ways this is the perfect visual accompaniment to the music coming through the headphones, Cloud To Ground, the debut release by Minibus Pimps, the band put together by former Led Zeppelin bassist John Paul Jones and Norwegian improvisational artist, producer and musician Helge Sten, better known in more esoteric musical circles as Deathprod. This isn’t music in the conventional sense but an exploration of manipulated sound, twisted signals and mangled ideas that are several removes away from the instruments that created them. Yet this is a soundscape that’s never less than compelling as the musical potpourri contained within slowly, methodically and seductively compels and demands nothing less than the full attention of the listener.

Recorded live at a variety of venues and driven by the use of the Kyma computer system, an aural design environment that allows users infinite possibilities to create and bend sound, the pair have conjured a formidable collection of music that allows for personal interpretation and visual stimuli. Having already performed together in Supersilent - the avant-garde band formed by Norwegian jazz band Veslefrekk and Deathprod – and fascinated by the sonic opportunities afforded by digital technology, Minibus Pimps is the end result.

Taking shelter from the ominous weather outside, the Quietus meets the duo in a private members club and is pleasantly surprised to find a team given to high levels of laughter that belie the seriousness of their music. Indeed, John Paul Jones carries the demeanour of a mischievous schoolboy just waiting for a whoopee cushion to be sat on while the intense physical presence of Helge Sten masks a personality only to eager to join in with his cohort’s sense of humour.

How did this project come about?

John Paul Jones: Well, it came out of Supersilent. The first time I played with Supersilent was in Kristiansand in 2010 and that was just a short solo piece that I did with bass guitar and my Kyma computer system. Helge was interested in the computer system and we just got talking about it and we found that we had quite a lot in common. I’d played with Supersilent and I’d enjoyed that immensely and we somehow made one of the top 25 jazz gigs of the year in Jazzwise magazine but we ended up talking about computer systems. But how did we actually get together for our first gig?

Helge Sten: I’d acquired a system and if you don’t put a lot of work and effort into it then it’s a waste of money. It’s really complex and you really have to learn it. But I thought it’d be interesting to hear how my programming sounded with John’s programme so that’s how the discussion came about. So we started this about three years ago.

So it’s fair to say that you view these computer systems as another instrument then?

JPJ: Yes, exactly so.

What were the objectives and motivation behind this project?

JPJ: To make exciting music and to play it. It’s one thing to do it inside the studio but the energy you can get in a live situation is quite different; you go to different places. We’d been invited back as Supersilent to Kristiansand and by that time we were already talking about Kyma and we decided to do something together with the two systems. The systems weren’t hooked up; we used them separately and we communicated on an audio and musical level. Although, actually, connecting them together could be the next step.

HS: It is possible!

JPJ: It is possible. I could process your stuff and you could process my stuff without either of us quite knowing what’s going to happen. That could be good fun.

What does using these systems give you that conventional instrumentation doesn’t?

JPJ: A wider sound palette.

HS: You can build your own processor. It’s interesting because I make different sounding programmes than John does and when that melds together it’s really exciting. And also, we can troubleshoot each other if we have a problem.

You’re both respected musicians in your respective fields but what did you bond on?

JPJ: Probably the improvisation. We’re both used to improvising on stage. I remember I used to do it with Zeppelin, apart from taking the solos, but there was a point in ‘No Quarter’ where I would go to a piano and literally have not much idea of what I was going to play and I’d just sit down and work out where I was going to go. Because what else can you do? I can’t just do nothing so I had to come up with something pretty quick! So I’m used to just doing stuff and Helge’s done that too, especially with Supersilent.

HS: Yeah, I really, really enjoy that kind of environment where you can literally compose music in real time. That’s how I see it; it’s not improvised music in a European style, it’s a different thing. For me, it’s about composing music but in a different time scale.

What I find so interesting about improvised music is the chemistry between the players involved that’s based on how well they know each other on a musical and personal level and how that helps the music. How well did you know each other on those levels before you started all this?

JPJ: For me, that’s two questions. We didn’t know each other but we felt comfortable with each other because we knew what we both knew, as it were. And we both looked at this composition in the same way – we would make music in real time. It wasn’t just a bit here and a bit there; you have to make a whole. With the computers, what you have is an improvisation that involves several different processes so you kind of know the different frameworks that are available to you. How you put those together are improvised but there are different sound worlds that are kind of set and that really is the compositional part of it. We know what each other are going to use but we don’t know when we’re going to use them.

HS: There are programmes that have a very specific sound so when you open up that sound and play a guitar or a bass or a violin through it that creates the framework of the song. This means that sound becomes an instrument and the fact that we use these instruments means that we send a basic source through the system.

Are there sounds that you hope to achieve using this method or are the results fairly random?

JPJ: There’s a degree of random outcome but it’s got to work and make a whole. It’s got to sound good and move from there to there. It’s not just random noises. But it is a little bit of both.

HS: It’s quite an organic process. I mean, at some point during a concert I have to change the process but it has to happen at an appropriate time and that depends on what John is playing. I don’t know exactly what’s going to happen.

JPJ: But also, in a different musical situation you tend to explore the process that you’ve got in to in a different way. These are mini voyages of discovery. I’ll hear him do something in a processor and I’ll think, "Oooh! D’you know, I’ve got something somewhere and yes, let’s do this one and I know what I’m going to do with it to connect with what he’s doing and we’ll build from there." It’s the most fun you can have, I have to tell you!

It strikes me that this is music that would lend itself well to huge visual accompaniment. Have you considered doing a multi-media package?

JPJ: It would be great!

HS: That’s the beauty of music; it can be really visual. It’s always really exciting to get a good visual artist to work with…

JPJ: …but that would be a different project!

HS: But the main idea is to make music.

This really does sound like it would be a great album to drop some mushrooms to and watch the Aurora Borealis. What do you think would be the ideal location and conditions for listening to this?

JPJ: A really good sound system!

HS: This is what’s great about going into a store and buying an album; you can take it to the environment that you want and make it your own. That’s what’s great about this album - it doesn’t have the guidelines of a straight pop album. You can decide on your own what you want to do with it.

JPJ: So if it’s magic mushrooms and the Aurora Borealis than that’s fine! Is that what you’re planning to do?

It’s certainly on my list of things to do.

JPJ: Well let us know how it goes!

Are there any parameters that you set for yourselves here or is this something you disregard?

JPJ: To say "no" kind of leaves it wide open but "no" is the truth. It’s got to work. That’s the age-old art question – knowing if what you’re doing is in any way successful. And only artists kind of understand the word "successful". People can say, "Oh, I like that" and you think, "Yeah, but it doesn’t really work." You can’t really explain why it doesn’t work to anybody else who doesn’t do it.

HS: We have quite high standards.

JPJ: We do! And when we’re doing the sound design part and then designing the processes, most of the time we work separately but occasionally we work together and someone will come up with something and say, "Listen to this" and you’ll go, "Ah, that’s really good!" or we come with something and then look at each other say, "Nah, not really…" But that’s the same with all bands and all music. I mean, in Zeppelin nobody had to tell anybody else if something wasn’t working. It’s just something that you get to know. We trust each other musically. It goes back to what we were saying earlier. Without actually knowing each other personally for that long we both know what we know. We know that we’re both very experienced and that we know that we’ve got two pairs of good ears involved with this and that’s all that really matters.

My understanding is that this project was half-written, half-improvised. Does that mean that you had some established ideas that you used as a launch pad for the rest of the music that followed?

HS: No. These programmes that we make are actually very specific and they make a very specific sound which then leads to something as specific as a song. So that part is written and then the actual execution on stage is very fluid. You can then move very freely within the processes but the actual programming involves a lot of work and lot of effort in how we can then shape an actual piece of music. But it’s not like writing sheet music. When you’re working with sound then that’s a completely different way of writing music; you’re using sound as an instrument.

Cloud To Ground is an incredibly dark album. Is this reflecting a worldview or simply sounds that you’re interested in? Where is it coming from?

HS: I guess that it comes from sounds that are interesting. I don’t think it’s purposely driven in a dark direction…

JPJ: …it’s how it comes out.

HS: It’s probably not a very jolly album but it has a lot of light and shade and layers. I think it’s open to interpretation.

JPJ: Maybe it’s the weather? It’s a northern European/Scandinavian thing, perhaps.

HS: You can’t avoid your surroundings. We certainly wouldn’t be making the same music if it had been made in Cuba!

JPJ: As Albert King said: “You can’t write the blues sitting under a palm tree”!

Now, I’ve got to ask you the obligatory Led Zeppelin question…

JPJ: Well he can answer it!

Well, it is aimed at both of you but what do you think is the most avant-garde moment in Led Zeppelin’s catalogue?

JPJ: Er, probably ‘The Crunge’! I don’t know! What do you say?

Well, if I could, I’d put the intro to ‘In The Evening’ in a 20-minute loop.

JPJ: Oh, thank you! That was me! Jimmy put some guitars on it, too, but I did that on the Yamaha GX-1. I found this programme where you have all the filters on the edge where they break up and keep trying to do something else and they keep coming back again. Yeah, that was great, that.

HS: I think there’s so much interesting stuff going on in all of their music. There’s so much variety and energy going on there and that’s what sets it apart from so much other music.

I love that photograph of you posing with a passed out fan backstage who was wearing a Led Zeppelin t-shirt…

JPJ: That wasn’t a drunk fan; that was the drunk drummer of The Maccabees! His band mates put us up to it – me and Dave Grohl. They said, "Our drummer’s asleep – would you come and take a photo with him?" They did ask other bands to do it but he was wearing a Zeppelin T-shirt so it seemed kind of appropriate! But it was funny and then Dave followed me and did his one!

So what’s next for Minibus Pimps? Is this something that you’re going to pursue?

JPJ: Oh yeah, but we’re both very busy people. We’d like to do some more sound design and more programming. But it all takes quite a lot of time to prepare for these things even though it’s all improvised. It’s very time consuming.

Cloud To Ground will be released on March 3 via SusannaSonata and you can pre-order it from Boomkat or Rough Trade