U2 have always striven for a new sound on each of the records they make, and during the sessions for their latest album, their aim was once again 'to construct a new sound for U2 whilst still making them sound like U2'. To this end, they brought in production wizard Flood and Scottish dance artist Howie B and set about new methods of recording. PAUL TINGEN investigates the art of Pop...

Other bands and artists with long careers have found different answers to the tensions between commercial demand and artistic renewal. The Rolling Stones will sound forever like, well, The Rolling Stones; and David Bowie has changed his style so many times that he's alienated and bewildered many of his fans. U2 have trodden carefully between these two extremes, first changing direction from their early, raw sound with the more intimate and colourful The Unforgettable Fire (1984), produced by Brian Eno; then with The Joshua Tree (1987), which featured a more rootsy sound, and was produced by Eno and Daniel Lanois. The next big re-invention happened with Achtung Baby (1991), a grungy, desperate, distorted affair that was produced by Lanois, with help from Eno. Zooropa (1993), produced by The Edge, Eno and Flood, was their most recent album under the group name until this year. Recorded in short, spontaneous outbursts during their Zooropa tour, the album was an experimental but rather disjointed record that might have been better as a 4-track EP (which was how it was originally planned -- Engineer Robbie Adams described the recording process for both Zooropa and Achtung Baby in SOS March '94). And now, there's Pop. The hit single 'Discothèque' that preceded the release of the latest album immediately made clear that this was U2 -- but not as we know them. The record completely lacked 'classic' U2 trademarks (such as Larry Mullen's big drum sound, Edge's sustained guitar-playing and Bono's falsetto vocals) -- and the prominent dance influences also surprised many people. When the news of the new album's title was released, some were eager to jump to the conclusion that U2 had bowed to the pressures of commerce and fashion. Was this a re-invention too far?

In fact, large parts of Pop are excellent. There are a number of truly great songs, such as 'If God Will Send His Angels', 'Staring At The Sun', and 'Please', and much of the album is executed in new and fresh ways, with many innovative, dry-sounding multi-rhythmic drum patterns, highly unusual guitar textures, and a relaxed and mostly understated Bono. And yet, somehow, it still sounds like U2. So, how did they manage to successfully reinvent themselves again? The answer can in part be found in changes in the personnel with which U2 surrounded themselves for the making of this album. Pop is the first U2 album since Rattle & Hum (1989) which does not feature either Lanois or Eno. Instead the album was produced mainly by long-standing U2 engineer, mixer and Zooropa co-producer Flood, with lots of help from Scottish DJ and dance artist Howie B. They also had some help from Steve Osborne (known for his work as one half of the remix/production team he formed with DJ-turned producer Paul Oakenfold), as well as dance producer Nellee Hooper (who produced Björk's Post and Massive Attack's Protection). Howie B's account of his work on Pop can be found elsewhere in this article, but to find out about the making of Pop from the man who is credited as main or sole producer on seven of Pop's 12 songs, and co-producer on the other five tracks, I travelled to North-West London, to meet Flood in his own studio.

Flood is a busy man, and this was reflected in the state of his studio, which was full of flightcases and cardboard boxes (see the panel on the studio elsewhere in this article). He started the interview by explaining the idea behind the large Pop production team: "Part of U2's working method is bouncing off each other's and other people's ideas. With the exception of Rattle & Hum, they've always had two or three people on the production side; if they have only one producer, they're likely to veer towards one particular style, and that's not what they want. So on Pop, they asked Howie B to be there because he comes from a dance music background, and I was there because I come from a radically different background. Basically, the idea is to throw everybody into the studio at the same time, and see how they rub off each other."

Flood's background is not easily defined, but it is definitely not in dance music and related music styles. His list of production, engineering and mixing credits is so eclectic that it almost defies definition, including '80s synth pop (Soft Cell, Depeche Mode and Erasure), experimental industrial (Nine Inch Nails, Nitzer Ebb and Renegade Soundwave), experimental and straightforward rock (PJ Harvey and Nick Cave as well as The Charlatans), trip-hop (a remix of the Massive Attack single 'Protection'), and even Tom Jones (the single 'A Girl Like You'). Eclectic indeed; the only common aspect is that it's almost all experimental in nature. Flood started this leftfield career in 1978 when he was taken on as runner at Battery Studios in London, and was named Flood within weeks because of the floods of tea that he made one particular late-night session! He continued his engineering apprenticeship at Marcus and then at Trident Studios, going fully freelance as an engineer/producer in 1985. His involvement with U2 goes as far back as The Joshua Tree in 1987, which he engineered. Flood picks up the story: "After The Joshua Tree, I worked on Achtung Baby, which I engineered and mixed, and on which I also had creative input. And then Zooropa was very much Eno, Edge and myself working on songs individually and then taking what we'd done to the other and seeing what they did with it. It was an experimental record: we weren't very precious about what we were doing." On Pop, Flood graduated to the role of sole producer on most of the tracks, keeping his hands free to leave almost all engineering to Mark 'Spike' Stent (known for his work with Massive Attack) and Howie B. The youthful-looking Flood (he's 36, but could easily go for 26), explained the division of labour on Pop in more detail: "On Pop I was what you could call the creative coordinator. There were some tracks where I didn't necessarily have a major involvement, hence the four co-production credits with Howie, and the one with Steve Osborne, but ultimately the buck stopped with me. I had the role of the creative supervisor who judged what worked and didn't work."

Steve Osborne also worked on some of the tracks on Pop which were considered as potential singles, like 'Do You Feel Loved', 'Staring At The Sun' and 'Gone'. As Flood explains, Steve was brought in when these tracks were two-thirds finished, "as someone from the outside who could give an objective opinion, and be ruthless about what they were doing"; a role that U2 had in the past given to the producer of their early albums, Steve Lillywhite. The other name producer who was involved in the making of Pop, Nellee Hooper, played a large role in the germination of the album. Flood: "U2 started off work on Pop in the summer of 1995, when they did sessions with Nellee in London, France and Ireland. During the autumn, Howie and I came in, and we all worked together for quite a while. I think the idea was to combine the influences of Nellee, Howie and me. What also really affected U2's way of working, and therefore the way the record turned out, was the fact that Larry had a bad back problem and couldn't play very much. He had major surgery on his back over Christmas '95, so during January '96 we didn't work on the album. Normally, U2 work their ideas out in the studio with the four of them actually playing together. But when Larry couldn't play, we had to find new ways of working."

Although it was tough on poor Larry Mullen, his back problems did prove to be a musical blessing in disguise, as they forced U2 out of their usual methods of working. This in turn opened the doors to new influences, which is where Howie B came in. Awarded the loose and potentially confusing role of 'DJ and vibes' (see the 'B Here Now' box elsewhere in this article), Howie ended up with Pop sleeve credits for 'inspirational decks' -- ie. turntables -- and 'loops' on several tracks. Flood explained what it all meant: "Howie would be playing all kinds of records to inspire the band and for them to improvise to. That could be anything from a jazz trumpet solo to a super groove funk thing, with no holds barred. We also programmed drum loops, or took things from sample CDs; anything to get the ball rolling. U2 arrive in the studio with very little finished material; on Pop, the only songs that were more or less there before we started were 'Wake Up Dead Man', which was left over from the Zooropa sessions, and 'If You Wear That Velvet Dress', which came out of the pre-production sessions with Nellee. I think 'Mofo' was also partly written beforehand, and so was 'Staring At The Sun'. But all these songs changed radically as we kept working on them."

Work with the record decks and drum loops happened mostly during September-December 1995 at Hanover, a warehouse in Dublin that U2 have transformed into a rehearsal space/recording studio, featuring an old Neve desk much loved by Howie B, and Otari MTR90 and MTR100 24-track tape machines. For sequencing, Howie B and Flood used an Atari with ageing Creator software, while the sampling was handled by an Akai S1000, S1100, and S3200, and (in Flood's case) a Kurzweil K2000. Steve Osborne worked with Cubase on the Mac, while programmer and keyboardist Marius de Vries favoured Logic Audio. According to Flood, some 30-40 pieces of music emerged during this period, ranging from songs to jams to the merest germs of ideas. When work on the album re-started in February 1996, the challenge was to take these musical bits and pieces to the next stage.

Flood: "After Larry returned, there were another three months during which the band, Howie, Nellee and myself tried to re-work all this stuff, and take it one step further. We had to be careful to not push Larry too hard at the same time, because he was still recovering. We took what we had and got the band to play to it and work it into their own idiom, whilst incorporating a dance ethic. This has to do with the way you use loops and how that affects your music. The groove-orientated way of making music can be a trap when there's no song; you end up just ploughing along on one riff. So you have to try to get the groove and the song, and do it so that it sounds like the band, and do it so that it sounds like something new."

Flood called this period "quite difficult", because "it was all this feeling around, and not quite knowing where we were going. We first started with trying to get the band to integrate the moods of the pieces, so it wouldn't sound like U2 on top of a load of loops, and then we tried to get the loops themselves back into the U2 mould. Larry listened to the feels of the drum loops, and recreated them himself; we then used his loops as a basis for him and the band to play live on top of. So we gradually replaced all inspirational loops and samples, apart from a few that were too integral. We credited those on the CD cover, leaving the sample in the song in a few cases. In other cases, like with Naked Funk and 'You Showed Me' by Gene Clark and Roger McGuinn, we just acknowledged their influence. But it was quite hard for the band to shift from having played to loops of other people to playing to loops of themselves. We felt it was essential to do that, though, because you can get very lazy with samples. They're an easy way to get the ball rolling, but you're always in danger of sounding like some basic samples with the band on top. You're in danger of being dictated to by what's there, rather than saying: 'this is just our springboard'."

Sampling was nevertheless not abandoned. In keeping with the band's aim to incorporate a dance music ethic, the crew then went on to sample, loop, and fly in all members of U2, not just the drums. Flood: "There were many guitar and vocal loops. On 'Mofo' there are little guitar and vocal samples that they played and we sampled. We selected the bits that we liked, and then Edge played them back in off a keyboard. We did that quite a lot, and ended up with maybe 20 or 25 percent of the sounds on the album being loops, samples, or programmed stuff, although these parts were always supplementary; we took great care not to clutter things. That reflected another aim that we had, and that also came from the dance world: we wanted to give the illusion of there being a lot of space in the music. In dance music, you only bring things in when you really want them, and even then you'll hold off for ages. Everything has a reason for being there. That affected how the music came out a great deal. It's knowing when to leave out, rather than when to put in, and knowing when to change things in subtle ways, by gradually enhancing them with an effect as the song moves on, or taking them out for another section."

Giving the illusion of space is certainly something that the production team succeeded in on Pop, for even though some of the arrangements are quite complex, there's a clarity and logic to them, and Mullen's multi-layered rhythmic patterns, that is impressive and a far cry from many of their previous efforts. Flood acknowledges (a point backed up by Howie B elsewhere in this article) that this sense of space was also achieved by carefully layering all the elements of the arrangements and giving them places in the frequency spectrum where they didn't get into each other's way, and also by applying relatively little reverb in the mix. But before it came to the mix, shaping Pop's songs and arrangements into their final, carefully crafted form took a lot of blood, sweat and tears. According to Flood, it was a continuous process of invention and re-invention that continued until the very last moment: "People ask me when I know a song is finished, and I say: 'when it's finished'. We had three different mixes of 'Mofo', and during mastering in November '96 in New York, I edited a final version of 'Mofo' from these three mixes. So even during mastering, we were trying to push the song to another level. It was a long process of experimentation; the album didn't actually come together until the last few months. Nellee left in in May '96 because he had commitments to work on the Romeo & Juliet film score, and it took a couple of months after that before things really started to take shape. They changed radically during the last few months, which is why Nellee isn't credited."

The 'last-minute' edits to 'Mofo' seem typical of the band's working methods during the construction of Pop. According to Flood, U2 always expect their production team to challenge them with, as he puts it, "bold strokes". Flood continued: "Even though there was a lot of programming and sampling going on, most of the time things went straight to tape. Laying something to tape, and committing yourself, rather than keeping them 'virtual', as they are with MIDI or on hard disk, is a bold stroke. When you change as much as U2 does, you do need to commit yourself somewhere. People will work to what's on tape as being the part. That's why I prefer to work with analogue tape [see the 'Flood On Analogue' box]. There were periods of doing rough mixes, during which we tried out different arrangements, and they would always be bold moves, rather than nitpicking here and there, because the band reacts far more strongly to that. Like on 'Please' -- for ages the rhythm track played all the way through the track. It's a fairly tight groove/bass thing, and then we suddenly decided to drop out the rhythm section in the middle and add a load of strings and these weird synthetic sounds at the end of that break. With those three simple moves, you've created something very strong, and it's far simpler and more effective than just changing the hi-hat pattern in the chorus or something. Of course, we get into that too, but generally with U2, it has to be bold, it has to be strong. Otherwise, you get stuck working on small things that get magnified out of all proportion."

Another bold stroke was the band's move to Miami halfway through the project. They went there to do a photo shoot, but then ended up recording for 10 days in South Beach Studios, because "the change of environment gave them new inspiration". Unsurprisingly, the track 'Miami' was written, and in part recorded there, as well as a "a lot of drum stuff, replacing loops and overdubs."

When listening to Flood's descriptions of Pop's recording process, the question arises of how on earth he kept his 24-track analogue tapes from wearing out over the course of more than a year of chopping and changing, and replacing overdubs. The answer, according to Flood, lies in the huge amount of submixes that he did to other analogue 24-track tapes, and the 'fatting' process that Robbie Adams described in SOS three years ago: "I did mixes of key components of songs to other multitracks and then did edits on that multitrack, making sure I kept track of everything with timecode. I never worked on more than one multitrack tape at the same time, because synchronisation always takes time and awareness. But because of all the submixes and overdubs to and fro, there are some songs on which the basic rhythm track is fourth generation. We also did 'fatting' to a sync'ed Tascam DA88; when someone wanted to quickly try some guitar overdubs, or do loads of vocal overdubs, and the 24-track was full, we put the overdub down onto the DA88. Then, later, you can select the bits you want, and fly them back onto the multitrack. The DA88 was also used for archiving."

Flood repeated several times during the interview that the main aim during the recording sessions of Pop was to "try to construct a new sound for U2 whilst still making them sound like U2." As well as by incorporating new musical influences, especially those of dance music, this was also done by consciously deconstructing mannerisms and sounds that the band had been using in the past; a lot of work went into developing new sounds and new ways of performing for all four members. As described above, drummer Larry Mullen was forced into this because of his back problem, and consequently had to react to loops from other records, sample CDs or programmed drums, whereas in the past, it had always been a rule that any loops and programmed drum patterns would only be taken from Larry's own drum playing. But as Flood explains, it wasn't just the working methods, it was also the sounds that were changed for Pop: "Larry was always known for his high-pitched ringy snare, and big drum sound, and this time we were trying to get a drum sound that was bone dry. It was very simple; we tuned down his snare to see how he reacted off that. Big drum sounds do work, and they're exciting, so it's very easy to get lulled into using them. But you have to think how you can do things in a different way; you have to keep pushing and pushing, and the beauty of working with U2 is that that is what they want." [see the 'Deconstructing Drums' box for more on how Flood miked up Mullen's drums].

To change Adam Clayton's bass sound, the team worked a lot with heavy processing, to the extent that several tracks sound as if they feature keyboard bass, but apparently it's all Clayton playing, with the exception of most of 'Mofo', which is indeed a keyboard bass. As far as Edge was concerned, he apparently wanted to show himself moving on. Flood: "Edge has been given this tag of having a certain type of sound, which isn't really fair, because on the last two or three albums he's already moved away from it; but people still perceive him as the man with the echoey guitar sound. So he was up for trying out all sorts of ideas, from using cheap pedals and getting the most ridiculous sounds, like in 'Discothèque', to very straight, naked guitar sounds, like in 'The Playboy Mansion'. The guitar sound that starts 'Discothèque' was him playing an acoustic guitar through a ridiculously loud amp and a filter pedal. I was sitting next to him without any headphones, so I couldn't hear the track at all; I was fiddling with the pedal. We then processed the guitar through an ARP 2600 synth, getting a different feel again. The nasty distorted guitar in the break is Edge playing through a Big Cheese, an effects pedal made by Lovetone. We wanted to shock with that sound, rather than: 'here comes the break and the really nice sound.' It takes you aback, and stands for something, and many songs were like that."

Bono also wanted to take his singing into new territories, and so he and Flood discussed his voice right at the beginning of making the album. "I think Bono is one of the great singers of our time, but he was very conscious of areas that he felt he'd gone into too often, like the bombastic style and his use of falsetto singing. So a lot of effort went into getting him to come over in a different way. It was a process of trying to make him sound as intimate and upfront and raw as we could -- so that you get his emotional involvement with the songs through the lyrics and the way he reacts to the music -- without him having to go to 11 all the time. All his vocals were recorded with a Shure SM58, as usual, and then went through a Neve mic preamp, and had a little bit of valve compression added from an LA2 or a Summit. We only used extreme effects on his voice during the recording, for him to get himself into a different place, and then, gradually, we pulled most effects out. We didn't add many effects to his voice during the mix. In fact, we didn't add many effects in general in the mix. There is a lot of effects processing on the album, but much of it was added during recording."

The effects units actually used (described iconoclastically by Flood as "whatever worked") ranged from budget Zoom 9200 and 9010 units to more expensive gear like the Lexicon PCM70 and Yamaha SPX1000, as well as the unashamedly pro Eventide H3000 and H4000 ("the ultimate piece of outboard gear"). But it would seem that in their use of these tools, too, the production team were guided by a well-developed set of ethics, as Flood explains: "I have been cited as using a lot of effects on U2 records in the past, but on this album we wanted to create space and avoid clutter, so we didn't use effects in a standard way, like putting reverb on the vocals because it's the done thing. We were only using effects for really creative purposes. They had to be there for a reason. We also tried to approach the whole mix like that. Instead of going through the ludicrous practice of spending five hours solo'ing the bass drum sound, EQing it and looking for the right effect for it, and then finding that it doesn't fit in context, we would simply bring everything up, get the balance right, and then go: 'OK, so what's missing or wrong?' If the track was a bit dull, we'd add some high to the predominant sound, or even to the whole mix. We were always listening to things in context."

Flood recounted that half the album was mixed at Hanover and the other half at Dublin's Windmill Lane Studios. Echoing Howie B's statements about approaching the mixing desk like a musical instrument (see Howie B's box on effects and mixing), Flood stressed that non-automated mixing was also important to the team: "When you have two or three people sitting at a desk doing a mix, pushing and pulling and changing the music, it becomes like a performance. I like the excitement of doing that and the excitement at the end when you go: 'yeah, this is it!' After all these months of creating, you want to be really excited about getting your final result. I hate the anti-climax with automation where you've just done the final version of your mix in the computer, and you go: 'oh, I'll have a cup of tea now, and then put it down.' Ultimately, doing a live mix with a group of people at the desk follows the same principle as we had for the making of the whole album: throw ideas around amongst everybody, so that people will be pushed into new territories and will react in a different way. My role as a producer in this project was to make sure that wherever they went, however new and unique the style, it would still sound like a U2 record. It had to become U2's best record so far, and if we hadn't achieved that, I would have felt that I had failed." From the evidence of Pop, Flood need not have sleepless nights.

"What I admire about U2 is this hunger, which they still have, for making a challenging record. They really do want to push the barriers back. The way they involved dance culture on this record was really good. It's not as if the album they've made is a club record, but there are definite influences from the club scene in there. It's very brave of them to take this stance."

When I asked Flood whether the last-minute edits he did on the Pop track 'Mofo' during mastering were performed with a digital editor, he reacted immediately: "You must be joking! I did it on half-inch tape". He also quickly added that he's a "bit of a diehard analogue fan." Apparently U2 and Howie B also have a love affair with analogue -- the reason why the band's studio has two Otari tape multitracks, the MTR90 and the MTR100. However, Flood loves analogue for reasons which are slightly different from those of the increasingly widespread back-to-analogue movement. For starters, he didn't argue for a moment that analogue actually sounds more accurate than digital, like many others: "Rock 'n roll isn't about accuracy, rock 'n roll is about feel. Analogue isn't accurate, but it is musical. I love the sound of it, especially at 15 inches per second, because I love what it does to the bottom end at that speed. And with Dolby SR, noise is not an issue. Analogue also has wonderful tape compression that's inherent to rock 'n roll. When you are aware of the fact that analogue isn't accurate, but realise what it can do, you can use the medium as if it's an effect."

Flood continued by saying "it's very dangerous to be negative about change, but it's also dangerous to assume that everything from the past is wrong. I think that a marriage of analogue and digital will give you something very powerful." He professed his love of digital effects, especially the Eventide H3000 and H4000, and stated that he liked hard disk recording and editing for the writing process. But with his argument that analogue isn't accurate but musical, he clearly didn't mean to imply that digital therefore sounds more accurate: "There are harmonics above 20KHz [the limit of human hearing] that influence the way we perceive music, even if we can't hear them as such. Digital can't even reproduce those. And all sounds produced by, or recorded on, digital have inherently the same quality: there's an element of blandness.

"There's not just a sonic, but also a psychological reason why I prefer recording on analogue. Particularily when working with a band like U2, when you're dealing with continuously changing options and approaches to each song, you want a point of focus. Digital recording is a bit like MIDI, it's way too fluid. You can all too easily chop and change things, and you have potential options all the time. Whereas when working with analogue tape, you commit yourself to some degree when you record something. You'll work harder at getting a part to fit into a piece of music, and that brings out the musicianship in people and the interaction between musicians. Even during an overdub, a musician is reacting to other musicians, and he or she will create a sound that pushes the song on in a different way. But when you're working digitally, things are so fluid that you often tend to not bother getting it right, and say: 'let's just play this little bit, and we'll chop and change it around later on.' To me, that's denying the ability of the musician."

How did you come to work with U2?

"I did a remix for them of a Leonard Cohen song called 'Hallelujah', which Bono did a version of. That's what made the first connection between me and the band. Then I worked with them on the 1995 Passengers album, which was a project they were involved with together with Brian Eno, and a few other people. So I was involved with a whole album before Pop. That was good, because it meant that when we started the album, I knew their methods of working."

What part did the band initially ask you to play on this record?

"At the beginning they were trying to find a role for me. My original title was 'DJ and Vibes'. It was a bit of a difficult title to be given, because some of the tunes didn't need that kind of input -- it's not as though there's scratching and loops all over the record. And vibes... that's a really difficult word to describe, and to put your finger on. So it was a bit ad hoc at first. As we got further and further into the project, the role I was playing came out -- I was co-producer, engineer, and mixer."

As far as the credit goes, it says you produced four tracks on the record, but were you there for all the sessions?

"Yes. On the tracks I didn't produce I was still in there, engineering, mixing, programming, playing keyboards, or being an aggravator!"

How did you work together with Flood and Steve Osborne? What were your roles?

"Well, Steve Osborne came in more just to mix certain songs. With Flood, the roles changed every time. There would be times when Flood was engineering, or where I'd be engineering. There were also weeks when Flood would be working in London on a completely different project, so I would step into the role of producer. That added an interesting dynamic, as there were things that Flood would do that I wouldn't do, and I think that made it more interesting for the band."

What do you think you added to the Pop project?

"I gave the band a direct line into club culture and freestyle DJing."

Are they into dance music?

"Yeah! We go out to clubs and gigs all the time. They are aware of what's going on on the dance scene, and maybe they're more aware now because of their relationship with me. I was also the person on the project who was constantly checking that we hadn't overworked a song; that it didn't sound laboured. That was a role that Flood was carrying out as well, but he did it in a different way. I would also play records for them; if we were in the middle of recording a tune, I would try turning them on to new things that were happening in the underground, or play old tunes with new stuff to encourage them. So there were different roles all the time, which made it really interesting for me. It was a demanding album to make -- even when it was easier, you still had to be working at 150 percent. We worked long hours, six days a week and sometimes seven -- but it was very enjoyable as well. When you work with people for that amount of time you become very close, and you give each other a lot of support. We were laughing an awful lot of the time, and that made for a really good record."

Flood's own studio is a rather chaotic-looking affair, where he clearly doesn't spend a lot of time -- apparently he only uses it for pre-production and the odd mix. Nevertheless, it's well-equipped, containing a Mackie 32:8 mixer, Tascam DA88 multitrack, and an Apple Mac with an Opcode Studio 5 MIDI interface which runs a Digidesign Pro Tools system. There was also a rack containing two Zoom effects units (the 9200 and 9010 used on the Pop sessions), an Akai S1000 sampler, an EMS Vocoder 3000, a Roland Super Jupiter module, a Helios EQ and mic preamp (also used with U2), a dbx 120XP bass enhancer, and an Ampex half-inch tape recorder. In the middle of the room stood two huge flightcases full of Flood's portable equipment, containing, amongst other things, an ADL Valve compressor, Summit compressors and preamps, the prized Eventide H3000 and H4000 processors, and even some vintage Neumann microphones from the '30s (Flood: "I call them the world's brightest and greatest"). But most eye-catching was the huge collection of vintage synths that graced the room: two enormous Roland System 700 synths, an ARP sequencer and 2600 synth, a Moog Series III, an EMS VCS3, a battered Yamaha SK10 string machine, an Oberheim 4-Voice and a Roland RE501 Chorus Echo.

"I started collecting these synths when I played in a band called Node, which was a four piece with all of us playing modular synths [see Node interview in SOS December '95], and when I was working with Mute Records bands like Nitzer Ebb and Renegade Soundwave. I use some of them during recording sessions; on Pop I used the ARP sequencer on 'Discothèque', and the backing track of 'Staring At The Sun' was played to the ARP running in free time, playing a really bizarre log drum-like sequence. I also put some guitar through the ARP 2600 on 'Mofo' and 'Please'. I used the VCS3 quite a bit on Pop as well. It's great because you can feed things into its line or mic input. I applied some VCS3 spring reverb and ring modulation in a few places, and used it a lot on the basic rhythm track of 'Gone'."

Three years ago, U2 engineer Robbie Adams explained in SOS how he recorded Larry Mullen's drums with just three mics, an approach he had picked up from Flood, who, said Adams, "is bored with all this traditional, big stereo nonsense." Flood explained that his way of recording drums was partly born from necessity, and partly from reading Mark Lewisohn's classic book on The Beatles' recording sessions: "When we were working on Achtung Baby, we had two drum kits set up, and I had very few channels on the desk, so that was a bit of a problem. I noticed from the photographs in the Beatles book how there was always one mic parked just above the drum kit. I thought it was maybe just for the photo or something, but then I saw it in other studio shots as well, and so, because of the problem I had with too few channels, I decided to try it out on one of the two kits. I put one mic on the bass drum -- an AKG D12 or Neumann U47 -- a Shure SM57 on the snare, and an SM58 as the overhead just above the kit.

"What started to happen was that people would prefer that drum sound, even though it's virtually mono. I also noticed that with Larry, who is a powerful drummer, when you put the drums in stereo you have to have the levels up higher on playback, whereas the mono drums were more powerful, even at lower levels. When I thought about it, I realised that if you're standing in front of a drum kit, you hear it in mono -- you don't hear the toms panning neatly from left to right in your ears. Also, a mic just above the kit compresses the sound. And that's the same effect that happens in the ears of a drummer or when you stand close to the kit; the sound is compressing in your ears because of the level of air pressure. So when you have a cheap, lo-fi overhead mic in that position, and add compression on a mic that's already compressing, it brings out the excitement, the same feel and natural balance that the drummer is getting."

"I've used the three-mic approach as a starting point ever since. You can do all sorts of things with it. For example, if the room you're recording in is rather dead, you can add a bit of room reverb just on the mad-sounding compressed mic. That will give the illusion of the drums having space, and yet the physical punch still comes from the middle. I will sometimes add two more overheads, like a 414 or 87, placed a bit higher up, or at the same height as the drummer's ears. A lot of the times we end up monitoring kick, snare and these higher overheads, and then if the track sounds a bit lame, we'll feed that extra low overhead mic in, which can bring out all the reflections that the drummer gets and that you may not hear normally. It's always good to experiment and listen to the sound the drummer gets in the room. When we were working on Pop in Miami, we were in a room that had very little character, so we put the two ambient mics right in the corner, pointing towards the ceiling, away from the drum kit, thus deliberately creating a woolly, booming drum sound that went well with the brightness of the drum kit. We were always pushing for character, and trying to stay as far away as possible from a generic rock drum sound."

What was U2's songwriting process for this record?

"Apart from maybe two songs which Bono and Edge had written before we started, during pre-production, it was fairly freestyle -- there were jams, and songs were built from those. After the end of that jam, we'd look at that track and see if there was anything worth keeping; and if there was, what it was and how we would keep working with that tune. For example, we might stop working that day, and each work away on our own with a cassette, thinking of our own melodic ideas, or structural ideas. Bono would then start looking for a character to the song; what it might be about, and so on. It was a quick process in one way, but also fairly slow in another; it was fairly quick to get the song started, and then it was a case of moulding that piece of music into a song. That's where the production started."

Which equipment did you use in the studio?

"The main thing I was using was record decks, which I would use to turn them onto stuff. I also used an Akai S3200 to sample bits of Larry's drumming, and put them into completely different songs. For example, on 'Please', there was a sampled loop of Larry's drums which I had taken from his drumming on 'If God Will Send His Angels', which was interesting. I made a lot of loops of Larry's playing, as well as guitar loops. I sampled Edge all the time, too, and made sequenced guitar sample patterns, which was an interesting thing to happen to Edge -- they'd never thought of doing that before. Sometimes I would sample, say, a guitar, but it wouldn't come back sounding like a guitar; it might sound more like a pneumatic drill, because I would take the raw sound and filter it, really destroy the guitar sound, and rebuild it into something completely different [see the 'Sampling' box for more on this].

"I also used a Clavia Nord Lead an awful lot, along with filter banks, voltage-controlled oscillators, and an Oberheim Echoplex for tape delays. The Nord Lead really shone out on this record -- it's a fantastic synth. I'd just started using it when we began the album, so it was a fresh sound for me. It's a very quick keyboard to get a sound out of, because the way you work it is very 'analogue', even though it's a digital synth. The analogue-style controls are fantastic. Apart from the Nord, we used a Roland Juno 106, an EMS VCS3, and a little bit of Yamaha DX7. There's also a Hammond in there, and a fair bit of Rhodes."

Is there anybody within the band that can use sequencers?

"Yeah! Larry uses sequencers; he'll demo some ideas, maybe program a groove for himself, and play around with it; and Edge uses a very basic sequencing package to work on ideas. But sequencers aren't really the best thing to work on sometimes... you can become a slave to them. There were a few keyboards sequenced on the album, and I sequenced some guitar loops and a few bits of percussion, but generally, sequencers were not used much on this record. When we did, we used an Atari running C-Lab Creator."

Which console and multitrack did you use on Pop?

"We used a Otari MTR90 multitrack, with mainly a 1972 Neve desk. Rupert Neve made that for EMI -- it was the first 24-buss desk that he made. It's a split console too, which was interesting, as most mixing and recording desks are in-line these days, and I did my apprenticeship on a split console. It was great to come back to that -- a split console has its own character, and the way you record and mix is a bit different. The desk was also a fantastic tool for me -- I used that like another instrument."

Is that how you achieved some of the amazing sounds on the album? For example the vocal treatments and heavy bass sounds all over the album, the echoes on the vocals and bass drum in 'If God Will Send His Angels', and the distorted drum sound on 'Miami'. Were these effects created during the mix or when recording?

"It was very easy to record the vocals; very little EQ, just a little compression, and off we went. Sometimes, depending on the song, there'd be an effect used later, but when we started off, it would just be Bono with his SM58 going for it. Sometimes he'd sing to an effect; delay, flanging, distortion or whatever, just to react to it. But it wasn't as if we spent three weeks looking for a particular vocal treatment; we didn't do that at all.

"The trick with the bass sounds is really to make sure the bass is there when you record it! Because later on, you can only bring out sounds that were already there. I didn't add anything; the bass was already there, it was just a case of putting it in a place where you can hear it. Sometimes that's purely a matter of level -- it can be as simple as making the bass track louder -- and sometimes you need to use EQ.

"On 'If God Will Send His Angels', there's no reverb at all on the drum kit, so again, the echoes you hear are just to do with the sound of the kit when it was recorded, and the balance that I set up later. On the vocals on that track, the reverb you hear is just an analogue plate reverb; two pieces of metal with a spring between them. The balance on that song is like the balance on all the others; there's nothing fancy going on there. It's the space that song happened in that gives it its incredible character.

"The drum sound from 'Miami' comes from quite a few things -- it's basically very extreme EQ used sparingly, on particular tracks. The main groove is actually just Larry's hi-hat, but it sounds like a mad engine running or something really crazy -- about as far away from a hi-hat as you can imagine. Part of the effect was deciding when to use it and when not to. Sometimes when you use something extreme and then take it away, the space that you leave when it's not there is just as extreme, even though there's no longer anything extreme going on! For me, the task in 'Miami' was to make it unlike anything else on the album, and also unlike anything else you'd ever have heard before.

"'Miami' was a live mix; I didn't use any computers or automation, which made it really interesting. Most of the album was like that, but with that track in particular, there was no need for automation, as it was a very simple track in the end; there were only maybe nine tracks of audio used on it. It was also more fun and more musical to do it live -- I think I got a fairly large sound out of just nine tracks, and several of the things that happen on it only happen because I was doing it live. If you go into a mix with preset rules -- you know, that you use this reverb on drums, and that processing on vocals -- I think it ends up sounding very straight, and very contrived. But if you go in with the approach that anything can happen, with no set rules, that's when it gets exciting. That's how I attack mixing. It makes it more interesting, and it's more creative. You open new doors that way; you discover things that haven't happened before. Like I said, the desk was a very important instrument in the making of this album, especially the way that me and Flood use it. It's something we can both play, the way that Edge can pick up a guitar and play a fantastic song. I can go onto a desk and use it in a way that no-one else will, and it's the same with Flood."

U2 have previously been quite controlled in their use of samples, employing only loops of their own playing, but it seems they were a lot freer this time around. Which tracks particularly benefited from the new approach?

"Well, we approached 'The Playboy Mansion' with a bit of a hip-hop attitude; and it worked really well. On that track, the rhythm track is two loops of Larry playing, and he's also playing live to those loops. So at some points, there are three drum kits going at once, in quite a controlled way -- the arrangement is particularly interesting. The track started off as a live jam, and then we took that and programmed it up. Larry went off into a side room and made some sample loops of him playing his kit, and gave the loops to me and Flood. It was the same with the guitars; there's a guitar riff which comes in in the verse and chorus, which is a sample of Edge playing."

As well as loops, are some of the drums we hear on the final album programmed?

"Not really; 95 percent of the drums on the record are 'real'. There are just the odd moments where you can hear loops; and it's fairly obvious where. 'The Playboy Mansion' is one of the places where people will say; 'OK, they've had a different attitude to recording here'. But on all the other songs, the drums are live."

I understand the track 'The Playboy Mansion' samples Gene Clark and Roger McGuinn's 'You Showed Me'

"No, we didn't sample that -- it was a Turtles song which I played them, and U2 were inspired by that. One of the guitar riffs Edge plays on 'The Playboy Mansion' is inspired by that song, but we didn't actually use any samples on it. Edge played the riff and made it his own, but we thought we'd better respect the fact that we had been inspired by that song; that's why there's the credit. That happened on a few other songs; another one was 'Do You Feel Loved', where the inspiration was a Naked Funk song."