How do you reason with two guys who once went to court over artistic ownership of a big rubber pig? That was Bob Ezrin's mission when he agreed to produce 'The Wall' with David Gilmour and Roger Waters. The legendary tensions between the two feuding Floyds came to a head during sessions for 'The Wall' in 1979- which was why Ezrin was called in.

"My job was to be Henry Kissinger - to mediate between two dominant personalities," recalls Ezrin from the safe distance of 12 years. "Each one has a need to express himself in his own style. And sometimes those styles are very different."

Seasoned by sessions with Lou Reed, Alice Cooper and Kiss, Ezrin was the ideal man to co-produce 'The Wall'. He first discussed the project with Roger Waters "during the 'Animals' tour, in the back of a limousine on the way to Hamilton, Ontario. He [Waters] told me that because he felt so alienated, he had this concept of building a wall between the band and the audience. We kicked the idea around in the car. Honestly, I never expected anything to come of it."

But soon Ezrin found himself in the thick of Pink Floyd's most ambitious recording up to that time. No mere referee, he had plenty of his own ideas for 'The Wall': "I fought for the introduction of the orchestra on that record - the expansion of the Floyd's sound to something that was more orchestral, theatrical... 'filmic' is the word.

This became a big issue on "Comfortably Numb", which Dave saw as a more bare-bones track, with just bass, drums and guitar. Roger sided with me. So "Comfortably Numb" is a true collaboration - it's David's music, Roger's lyric and my orchestral chart."

David Gilmour's classic guitar solo on "Comfortably Numb" was cut using a combination of the guitarist's Hiwatt amps and Yamaha rotating speaker cabinets, Ezrin recalls. But with Gilmour, he adds, equipment is secondary to touch: "You can give him a ukulele and he'll make it sound like a Stradivarius. He's truly got the best set of hands with which I've ever worked.

People always ask me, 'How the hell did you get that astounding guitar sound at the end of "Another Brick in the Wall"?' That's just Dave DIRECT, with a little compression. We used a form of double compression: first we put the guitar through a very aggressive limiting amplifier, compressed that output, and overdrove it. The limiting amplifier makes it pop, and the compressor gives it a kind of density: the sound of being right in your face.

But still, it's nothing so involved that it would have made that part sound good if Dave's playing hadn't been so brilliant. That's his first take too!"

Ezrin was also called in to assist at the birth of the first (and, so far, the only) Pink Floyd studio album without Roger Waters: 1987's 'A Momentary Lapse of Reason'. Here a different kind of artistic debate arose. While Gilmour was keen to strike out in new musical directions, Ezrin felt a certain obligation to produce a record that wouldn't disappoint the expectations of long-time Floyd fans. "People are used to Pink Floyd delivering atmospheric, philosophical records, with lots of effects and ear candy," says Ezrin. "I didn't feel that a complete overhaul of the Pink Floyd sound or approach was called for at that time, particularly since Roger had left."

Given the disparate set of songs that had been written for the album, Ezrin and Gilmour keenly felt the need to find a common "thread" to hold them together. They found that thread in a most unexpected place: right under their feet. Ezrin and Gilmour were recording on the guitarist's studio boat, the Astoria, moored on the River Thames. "Working on that boat was the most magical recording experience I've ever had," says Ezrin. "Sitting every day and watching the geese fly, the school-kids rowing, and the little old English fishermen on the bank created a kind of river atmosphere that permeates the whole album."

On a more practical level, the floating studio posed a few problems when it came to engineering guitar sounds. "It's not a huge environment," explains Ezrin. "So we couldn't keep the amps in the same room with us, and we were forced to use slightly smaller amplifiers. But after playing around with them in the demo stages of the project, we found that we really like the sound. So a Fender Princeton and a little G&K amp became the backbone of Dave's guitar sound for that record." When the song "A New Machine" created the need for something slightly larger Ezrin and Gilmour responded on a grand scale. "We actually hired a 24-track truck and a huge P.A. system, and brought them inside the L.A. Sports Arena," the producer recalls.

"We had the whole venue to ourselves, and we piped Dave's guitar tracks out into the sports arena and re-recorded them in 3D. So the tracks that originally came from a teeny little Gallien-Kruger and a teeny little Fender, but piped through this enormous P.A. out into a sports arena, sound like the Guitar From Hell."