Do you have a preference of a venue, or does it make a difference once you pick up a guitar and start playing?

It's all to do with the crowd in the house. If they're behind us and the communication is there, I don't really think so much about the bricks and mortar. The crowds vary night-by-night, city-by-city; it's really hard to say if I have a favorite place to play. Wherever the show's going off, that's my favorite.

You have this weeklong run on the "The Late Show With David Letterman," have U2 ever been a "house band" before, or had a residency?

Very early on we did in our hometown of Dublin; we played in a few bars on a regular Thursday night when we were first making our first album and first few singles. It was at the Baggot Inn on Baggot Street in Dublin. We also did a string of shows in July one year, it might have been 1979. We called them "the Jingle Balls" because we decked out the entire club in Christmas decorations in the middle of summer. Four or five nights with that theme, that was a lot fun. That was in a club called McGonagles, which is no longer there. Since then we've not done anything like this, so [residency isn't] a totally new experience, but something we haven't done in many, many years.

Let's talk about the new record, "No Line On The Horizon. It's one that really seems to take hold after repeated listenings. Your part on the record includes lots of slide work and soloing along with the type of playing you and the band traditionally are known for.

I had a great opportunity on this record to explore new guitar tones. In the compositional phase we were really trying a lot of experiments, which is always great for me. It means I can take solos here and there because we can actually write them into a song and make sense of them.

I hate just putting in a solo for no good reason, but in this case they all have important roles to play compositionally, and that's my favorite kind of guitar playing. I'm a big fan of guitar players who really work up solos that have themes and an emotional component, as opposed to just the pyrotechnic approach, which I think is all too common.

Some of the solos are in odd places in the structure of the song, but seem well conceived when they do show up.

I seemed to end up going to the slide a lot on this album. [Because of] the architectural way this record was put together, with these very intricate loops that we often played against, I think it really needed some sort of lyrical component which would offset that very structured quality to the sound.

We work a lot in contrasts, I think. We start off with something that's very inorganic, very synthetic, then we put on the organic elements. That approach has worked really well on a lot of these songs. We even have

Larry Mullen playing an electronic drum kit, which has all the feel of a drummer but sonically it just doesn't sound conventional. It's slightly at odds with the preconceived idea of what Larry's drums sound like. It was an interesting experiment. He at first wasn't 100% sure about it, but I think he really got into it and developed new ways of playing as a result.

That's the upside of experimenting; we make discoveries as musicians, as songwriters as composers as lyricists. We end up places where we just would not have gone if we had just sat down and approached things in a traditional songwriterly fashion.

One example is "Stand Up Comedy." You have a real hard rock riff going there and then it turns into something about as funky as you guys get.

That song has a great groove. It really started as a groove and the guitar came out of that. It was fun. I had just done a film with Jimmy Page and Jack White ["It Might Get Loud"] and I was kind of fooling around with the idea of the guitar riff. I hadn't really used that songwriting form that much over the years, I think "The Fly" would be the best example. This was like exploring what is a fairly well established form, but trying to give it a spin and a twist so that it wasn't a direct homage, more like a reinterpretation.