“Why so glum?” asks Roger Waters with a smile as he strides into a conference room in an elegant Mayfair hotel.

Taking a seat on a low stage, Waters is here to announce a new batch of dates for his live production of The Wall, including one UK show for next September at Wembley Stadium. The Wall has been one of the most successful live tours of all time, with ticket sales in excess of $380 million. But perhaps more than the all-conquering statistics and the spectacle Waters and his crew intend to deliver (“8,000 pixels wide!”), Waters believes that The Wall still has a grim relevance. The shooting in 2005 of Brazilian Jean Charles de Menezes in the London underground by armed police officers inspired Waters to write a new song to add to The Wall shows. He speaks of “economic disparity” and “fiscal extremism”. But, he says, “I am still largely optimistic.”

In person, Waters looks like a kindly uncle, affable but faintly patrician, dressed in black shoes, blue jeans, black t-shirt and suit jacket. His grey hair is swept back and the makings of a beard are sprouting on his chin. 70 next year, his face is lined, but arguably he looks better now than he did during Pink Floyd’s imperial phase. For half an hour, Waters fields questions from a contingent of European journalists as well as some scooped off the internet (this event is being simultaneously broadcast online). His manner is relaxed and good-humoured, even feigning an electric shock when the microphone he’s using to address the audience starts feeding back.

Anyway, here’s the transcript of the press conference in full.

Why did you decide to bring the show to stadiums?

“That was a decision made some time ago. I had a great yen to go back to South America, where I had done the Dark Side Of The Moon tour and had a fantastic time. In South America, because they don’t play basketball or ice hockey, they don’t have any arenas. So you either play in a samba club or in a soccer stadium, there is no alternative. The Wall wouldn’t really fit in a little club, so we had to play stadiums. That’s why we developed this show that we’re going to Europe with, which has all this extra visual information to make it more watchable in a big, outdoor space.”

How did you go about topping the spectacle of the previous Wall tour of 2011?

“The projection surface is much wider. When we were indoors, we were projecting over 8,000 pixels wide. We’re now projecting 15,000 pixels, so it’s almost double the width. It’s like 130 metres to 140 metres across now the projection. So really that’s the main difference. But what it means is because it’s so much wider, it gives us the opportunity to use the bits at the side for imagery that we didn’t use when we were working indoors. The content is by and large the same, but for instance in the arena show, at the end of ‘Another Brick In The Wall: Part 2’, when the underground train comes through, that’s now 500 feet wide instead of 140 feet wide. So it’s just… a lot wider. It’s cool.

“I talked with [tour manager] Andrew Zweck and he said there is definitely a tour in Europe. If you want to go outdoors in Europe next year, there is definitely a tour there for you to do. You just have to decide whether you want to do this anymore or not. We had such a good time doing it in Australia and New Zealand and South America and North America and England that I said, ‘Yeah, please, I’d like to do it some more.’”

Are you planning to play any festivals?

“No, there are no plans to play festivals. You couldn’t play this show at a festival. The Showco roof we were using in South America and North America takes 26 blokes 6 days to build and it takes up all the space, so it would be impossible to do a show with other acts.”

What do you enjoy most about playing in stadiums?

“There is something about connecting with that many people outdoors that is extremely gratifying. When I was a kid, I didn’t get that experience, I didn’t like it. Back in 1975 and ’77 when we were touring with Pink Floyd and playing soccer stadiums I rather disliked it, it felt like we were very disconnected. But I think that disconnection was actually a reflection of the disconnection that existed in the band more than something about us and the audience. So when we’re setting up these gigs, I go up to the very back of the stadium, then we run some of the stuff and sit there, and I understand why people up there feel connected with what’s going on on stage. And with the music and the emotions expressed during the show. It’s just a bigger community.”

Would you like any politicians to come to your shows?

“I think it’s because, when I was in South America, I met Piñera, who’s President of Chile, and I met the President of Argentina, so those two. And I have meetings with various Ambassadors and people, talking about various things. I was approached by a journalist in Buenos Ares who’s trying to get the Falkland Islanders to get DNA testing on 123 Argentine soldiers who are interred in a cemetery on East Falkland. And we are making some progress in that. But it was because of that that I went and had a meeting with [Argentinian President] Cristina de Kirchner and she actually mentioned it in an address she made just after we’d been there. I sent a letter as well to Sharon Halford, I think her name is, who is the chair person of the legislative assembly of the Falkland Islands. I assumed it was Whitehall who would be able to say yes, you can send in these forensic teams from the Red Cross to identify these kids, but it’s the Falkland Islanders themselves. They’re a bit wary of it. So we’ll just keep exploring all diplomatic avenues, so the parents of these boys know which spot to go and put flowers on.”

Of all the songs you composed during this period, which ones do you most enjoy playing live?

“A lot of it is very enjoyable, but I think ‘Comfortably Numb’ is probably the highlight. There’s some stuff that Sean Evans, who’s done all the animation that we use in the show, has done which is so spectacular at a certain point in that song it’s always a good buzz. Though having said that, just before that, I’ve been in a hotel room singing ‘Nobody Home’ and I come out and I sing ‘Vera’ and I’m at the front of the stage but the audience are all looking at the screen watching this film of this young American girl greeting her father who’s come back from the war and it’s extremely moving. So I get to look at the first ten rows of the audience and there’s quite a lot of tears going on, and that’s extremely moving. I’m sort of anonymous and I get to experience what’s going on in the audience and that’s very moving.”

Do you think David Gilmour might make an appearance at one of the shows?

“I don’t think so, no. I haven’t had any conversations with David about that. I think it’s extremely unlikely. I think, by and large, David’s retired as far as I can tell, but you’d need to ask him that.”

Would you be keen?

“Me? It’s nothing to do with me.”

What particularly moments of the previous Wall tours moved you?

“Particular gig that springs to mind, which was in Porto Alegre, the first show we did in Brazil. The audience were extraordinary there. But I think it’s the half time stuff with the veterans. I invite vets from whatever country we’re in to come to the show. And at half time, I go and see them back stage and we shake hands and do photos and sign stuff, chat, whatever. That’s often a very moving time. Particularly countries that have had young men in combat in recent years, like North America and Great Britain, but all over the world. In Brazil, I went to see the vets, and I had no idea what to expect. I walked into this room and they were all about 100 years old. They were sweet, they couldn’t have been nicer. Because they were non-combatants in the Second World War, but a number of them had decided that they were going to fight the Nazis so they left Brazil and they went to either Canada or came to England. When we were in the States at one point, there was this older guy. You look round the room, and all the ones with no legs – and there’s a lot of them – they’re all from recent wars, from Iraq and Afghanistan, because these are all IED injuries. And then there are older guys, my age, they’re Vietnam veterans. Anyway, this one guy was somewhere in between. He stood in my way as I was leaving the room and he looked me in the eye and he put his hand out and he took hold of my hand, and I said ‘I’m glad you could come.’ He hadn’t been in the row of people getting photos or doing any of that stuff, and he said, ‘Your father would be proud of you.’ And I was really knocked sideways when this man said that to me. I confess, I struggled slightly before getting back on stage. That was very moving. But it always is with the vets. We never speak politics for obvious reasons.”

Are there any parts of the original Wall album you feel you could have done better? Or would you consider re-recording parts of it now?

“No. The answer would be, no, I wouldn’t go back and start doing it again. That’s a piece of work that was completed. We go on working on the visual aspects of the show and I have added one song. I added one song for theatrical reasons. It felt to me that there used to be three solos at the end of ‘Brick 2’. And night after night I was feeling that the third solo was a solo too long, a solo too far, so I decided to drop it and put another musical piece in, which took me maybe a couple of months on the road, working it out in my head, and then playing it and figuring out chords on a guitar and then working with the band. But I would never go back to a piece of work that I’ve done in the past and try to rewrite it.”

Why do you think The Wall has stood the test of time?

“The amount of time involved has changed, because it’s a lot longer than it was. I just think people understand that it’s true. I’m not pretending anything. I write what I feel. So people get that it’s real, that there’s no artifice in it. There may be a little bit of craft in it, but there’s no artifice. It’s just an expression of how I felt growing up.”

You have one new song in the set, “The Ballad Of Jean Charles de Menezes”. Are there any plans for any more new songs?

“I think it’s very unlikely I’ll make any other musical changes to the piece. There’s nowhere else in the piece where I feel it lurches to the halt like I explained with the guitar solo in Brick 2. The reason I wrote the little song about Jean Charles de Menezes was because his family sent his photo in. On my website, I ask people to send in photos of fallen loved ones, and that was one of the stories that was sent in. Because I’m English, I know the story about what happened at Stockwell tube that awful day. And then his family came to one of the shows, I think they came to Porto Alegre, and so I met with them there. So that was a special night with me. Because he’s up there, his picture is up there the whole time I’m singing that song and I dedicate it to him. I use that wherever we go. Normally, I try and figure out the phonetics of a short speech in the language of the country I’m going to. A number of years ago when I did my opera in Poznań, in Poland, I rather foolishly made a speech in Polish. Wow! It’s so hard to make those sounds. So whether or not I’ll attempt this in the Czech Republic and all the places we’re going to, I probably will. I’ll talk about where we must be if we give our governments, or the police of our governments too much power. The descent into tyranny is a very steep and slippery one.”

When you were first touring The Wall in 1979, did you feel that the technology wasn’t able to realise your creative vision?

“Yeah, the technology we worked with in 1979 was extremely problematic. The projection systems that we have now, which are all electronic, the projector is tiny, very, very powerful. In those days, we had three standard, cinema-style 35mm arc-lamp lit sprocketed projectors running off an extremely archaic system called MagLink. Didn’t even have 70mm in those days. It was very unreliable, very different to keep things in synch. So things have changed an awful lot in terms of the technology and projection, which has helped me and the other guys working on the visuals of the show hugely.”

How does that work performance now? Is it challenging on stage?

“The show is much bigger now than it was then. I think it is actually easier. It’s complex and there are more people involved in running the show. Obviously, if you’re focussing 35 projectors it’s different than focussing three, and so when we set the show up the last several hours of the process, Richard Turner and his team of projectionists focussing… how many projectors is it? 49? Obviously, they all have to run in synch and they’re lined up. For this new tour of Europe, we’re projecting from way further back to cut down on sightline problems that we had before. There’s a new generation of projectors coming out which we’re going to use now which means we can throw from a lot further away.”

You wrote on your website that you had finished a new song for an album called Heartland. What can you tell us about it?

“I knew I shouldn’t have said anything about it… When I was on the road during this last tour, I wrote one particular song that might be central to me making a new album. I really don’t want to talk much about it. I haven’t made an album since 1992, which is a long time, 20 years, and the reason I haven’t done that is not because I haven’t been writing songs it’s because I haven’t found within myself something coherent enough. Amused To Death was a very, very coherent and simple concept, and very easy to understand. Immediately you had the title, you knew what it was about. And I hadn’t found a central kernel of an idea around which to hang a new piece of work. And I think I’ve discovered that now, in this new song.”

Are you sad the world hasn’t become a better place than it was when The Wall was first released?

“Yes, I am. But I think it’s very easy for all of us to see the little piece of history that’s going by in real time as we live, as shorter or longer depending on your perspective than it actually is. There have been changes. I am still largely optimistic. Because it’s becoming easier and easier for us to communicate with one another across boundaries of idealogy and nationality that we human beings eventually will figure out the answers to the economic disparity that lies at the bottom of most of the fussing and fighting that goes on in the world, and that fuels the fires of both religious and political extremism. And also fiscal extremism, which prevent the majority of us from fulfilling our human potential to live good and happy lives and to bring up our children so that we by and large change the world for the better, as time unfolds. So although I would agree we’ve not made huge progress since 1979, I believe that we’ve made some, and we might be approaching a tipping point. Which way we’ll tip, of course, remains to be seen. But I think one had to at least cling to some kind of optimism. What was interesting about [Neil] Postman’s book, Amusing Ourselves To Death, which I took the title from to make my record, in the Forward he describes two bleak outlooks. One is the Orwellian outlook, the idea that we’re all taken over by the Thought Police and books are banned and burned, and the other is Huxley’s notions in Brave New World, and he sees a future which I think is much more credible than Orwell’s, where you don’t have to burn books because no one reads then anyway. They’re all too busy playing fucking video games, they’re not interested. That’s what really scares me. It’s when you see kids sitting at a table and they’re texting each other. I find it weird, but maybe that’s me being old. They are pleasured into non-existence.”

You can find The Wall Europe 2013 dates here