Bono says the guitar on The Fly is "the sound of Edge's brain"

Now celebrating its 30th birthday, Achtung Baby marked a turning point for U2 at a time in music where great change was happening round them; the grunge, industrial and Madchester scenes with dance's infiltration into the mainstream caused the band to shift their own sound following the huge global success of The Joshua Tree and Rattle And Hum era. But it was the Achtung Baby's first single that became a blueprint for their finest hour.

"I remember Paul McGuinness, our manager saying, 'Now Bono, you don't want to look like the band too stupid to have a good time at number one, do you?" chuckles Bono to broadcaster Jo Whiley in a recent Radio 2 interview looking back at the album with The Edge. 

"We'd been making these very serious photographs with Anton Corbijn in the desert – four very serious men. So yeah, we wanted to cut some space for ourselves - to break out of whatever that was, that image we'd built up for ourselves. 

"The images we'd made for albums like The Joshua Tree," the singer continues, "Anton was saying, 'I'm not shooting you as people, I'm shooting your music.' So really everything comes out of the music. The songs tell you want to do etc. So we wanted to find some material, some songs that would allow us to be the people that we were in our earlier incarnation with the band. Even in the late '70s, coming out of punk, we were a lot more surreal band and far less earnest."

The idea was in place. But for The Edge it meant channelling the music around him. 

"I just remember at that time being completely lost in music; the music that was coming out, and it was so diverse. The amazing Manchester-based movement that was the synthesis of club music and rock n' roll, but also there was this industrial music which was Einstürzende Neubauten, Nine Inch Nails and KMFDM. I was really taken by a lot of the 12-inches that were coming out around that time. 

"To me it was sonically such a rich time," continues The Edge. "You had this reestablishment of rock n' roll as a kind of rhythmic form, which was what Manchester was about. And then this kind of exploration of the sonics of industrial music which was so aggressive and so experimental. So this opportunity, this playpen opened up and I was just going for it."

The Fly became the amalgamation of all those ideas and the band insisted it became the album's lead single. 

"The reason we wanted it as the first single is it defined, in some ways, the whole theme of the album," explains The Edge. "It was a great lyric from Bono and the hallmark of it is the singer is a bunch of contradictions. From sublime through to the most absurd statements that are clearly untrue. And right at that moment we were starting to wake up to the fact that trying to be earnest, we were on a hiding to nothing. Actually, the more interesting thing is to own up to your contradictions and explore them.

"So The Fly gave Bono the chance to do that and as a theme it stretched right the way through the whole tour and really we've held on to that idea ever since. But that was the moment when that pivot happened." 

U2 had embraced the rock n' roll star image with both parody and sincerity. And the acclaimed Zoo TV tour found them blurring the lines between the two.

"It's somewhat psychotic," adds Bono, "but it's that Oscar Wilde line, 'the mask reveals the man' and you'll notice this at Halloween when you see people dressing up and out they come. People hadn't seen us as rock n' roll stars; we were the Pilgrim Fathers going through the desert. And so we got up there in some plastic pants and the next thing you know we started really quite enjoying being a rock n' roll star. And at first it was a parody, and then it got a little close to the bone.

"But The Fly, the sound of the guitar is the sound of The Edge's brain," continues Bono. "If you hear that 'ner ner ner nernernerner', if you lean close as I am now, you can hear that's the sound of The Edge's brain. And then this rant of lyrical aphorisms."

And U2 fans have one b-side demo to thank for not just The Fly but two other Achtung Baby tracks. 

"Because we were exploring rhythm we had this tune called The Lady With The Spinning Head and we couldn't seem to finish it, but in the course of trying to finish that we ended up with Zoo Station, Light My Way and The Fly! They all came out of that exploration. So failure, in our case, is often extremely productive."