LOS ANGELES — When Pink Floyd first took its concept album “The Wall” to the concert stage more than three decades ago, even lead singer and chief songwriter Roger Waters couldn’t have imagined a day when rock music might get any bigger.

But 32 years later, his magnum opus about the battle between individual freedoms and authoritarian oppression has magnified beyond Waters’ own expectations of yore. Now the man who once excoriated the voluminous expansion of the rock concert experience has helped institutionalize it.

“I famously hated playing to large numbers of people and playing in stadiums,” Waters said. “The outdoor version, which we developed for South America and which is so much bigger than the arena shows, illuminates the piece in ways we can’t and couldn’t do indoors,” he said.

For instance, in the arena version, the metaphorical wall that is gradually built through the course of the evening typically spans about 200 feet. At stadiums, it stretches out to about 500 feet.

The South American tour of “The Wall” broke attendance records there — nine sold-out shows at River Plate Stadium in Buenos Aires trounced the previous record of five at the same venue held by the Rolling Stones — and it’s been among the top-grossing concert draws in North America since he resurrected and updated the show in 2010.

Since bringing “The Wall” back, Waters, 68, has done more than 150 performances that have grossed $218 million in 27 countries.

It would be tempting to think that by now “The Wall” is a well-oiled machine with every element solidly in place down to the last microsecond of music and pixel of imagery.

“I take a hard drive straight home from every gig and then look at it the next day or the next night, and I write notes,” he said. “I don’t think there’s been a single day where I haven’t changed something.”
Conceptually, too, the show has grown from its origins as a polemic largely about the angst of one particular rock star.

“The new incarnation of ‘The Wall’ is completely unlike the 1980 version,” he said. “It’s developed into being much more of an international polemic, and it’s also much more moving,” he said, referring to images, many submitted by fans around the world, of family or friends killed in various wars over the past century.

“In those days it was about the internal struggle of me, when I was younger. It’s now much more about everybody else, much less about me, and what’s going on in politics, communication and all the stuff I care so deeply about. In consequence, lots of people in the audience weep. That makes me very happy, to be able to engage people to where they can empathize with others to the point where they weep.”

Ultimately, that’s the wall that Waters yearns to bring down with his ideas and his music, a campaign of engagement that often leaves him feeling another emotion he didn’t have much contact with three or four decades ago.

“As I sometimes say to the audience now, I’m so moved playing in these big places, being with a great band and seeing the audience’s response,” he said. “They get so emotional, and I’m so moved — I have to admit that 30 years ago I was famously hiding behind my own walls. I didn’t like being in big spaces with lots and lots of people. But in the intervening 30 years, I’ve changed.”