U2's show designer Willie Williams on the Elevation heart runway, 'organic LED' and the The PopMart mobile disco... that never was.

Willie was being interviewed by fan site Interference. Below we feature an extract, click the link at the end for the whole article. Click here to enter the wonderful world of the Willie Tour Diary, hundreds of entries from U2 shows across the world and down the years.

Interference: What is the most important element of show design when considering a live show?

WILLIE: The audience's experience. Even now I will often go to shows and get into the thick of the crowd to fully remember what the experience is like. After that you have to decide what kind of show it is that you want to do, then take it from there.

Interference: What is the process that transpires of designing a tour, and how long does that process normally take?

WILLIE: It depends entirely on the scale of the project. For a stadium-sized show, which will tour for a long time, the general rule of thumb is to allow about a year. That would be from the initial head scratching and abstract conversations right through till the first show. For an arena (indoor) tour, perhaps half that time, a musical in a theatre also takes about six months.

Interference: What piece of work are you most proud of?

WILLIE: Hard to say - its a little like having several children which you love for different reasons. ZooTV was the most astonishing tour I have ever done, but purely on a design level, I felt PopMart beat the pants of it. In a funny way though, I think the one I am most proud of is R.E.M.s 'Up' tour in '99. I made a forest of signs and symbols out of rope light, which completely filled the stage. It looked like Tokyo gone mad, but the entire thing fitted in half a truck and cost $12,000. The Kronos Quartet 'SunRings' show is way up there in my affections too. I am reworking that design for when they play the Brooklyn Academy of Music in October so by then I will probably have fallen in love with it all over again.

Interference: The satellite stages and heart-shaped runways add a great interactive element to the shows. Who came up with this idea? Can the idea be improved upon even further? WILLIE: Ever since about the Unforgettable Fire tour, Bono wanted a runway into the crowd, but safety problems were always cited to squash the idea. However, when we shot 'Rattle and Hum' in Arizona, there was this huge camera platform that ran right into the audience. After that Bono just refused point blank to take no for an answer, having seen it done once, so the ZooTV runway was the result.

More recently, it was a really interesting series of meetings and discussions which resulted in the heart stage for Elevation - quite a pure collaboration. Mark Fisher and I discussed lots of ideas before proposing anything to the band. I was keen to have a long stage which extended into the house so, for a joke really, I drew up a rendering which had the PopMart arch laid down on the floor of an arena. The middle was filled in, but the colours were the same as the arch had been - it was even the same size, 33m long. Bono looked at the drawing and added to lumps on the back end, making the heart shape, after which Adam suggested taking the middle out again so Larry wouldn't be left stranded miles from the audience. It took a lot of logistical wrangling to make it work practically, but that was where the idea started.

It worked so well - largely because all Bono had to do was walk and there was immediate drama. The ramp became lower as it progressed, so as he walked he descended into the crowd and there was never a moment when he had to stop and turn around, he could just keep going.

Read the rest of this interview at fan site Interference.com