Friday night, to kick off the weekend of celebration, marking the 40th anniversary of Pink Floyd's The Dark Side of the Moon, a handful of us escaped from the strong winds and sleet falling in the roads around St John's Wood, for the warmth and history of Abbey Road Studios.

We convened in the Floyd's favoured recording space, Studio 3, which Nick said was different to when they used to use it, as then, the control room was on the other side of the glass (where the studio space now is).

A full playback of the album from the SACD (played through some apparently eye-wateringly expensive surround speakers) followed an absorbing Q&A with Nick Mason, hosted by Mark Jeeves (Planet Rock Radio)...

- After this period of time since its release, do you listen to it differently?

I've never deliberately put on anything we've ever done, I think, just to take a listen to it, because basically I find you always listen for things that you think, 'I'd not do it like that now'. It's interesting because sometimes you do hear elements of it that you think, that DOES work. That's well done. Sadly, never the drums!

We were very proud of [The Dark Side of the Moon], and we were grateful that people were still interested in it [years after], but we were busy with the next thing, working on Wish You Were Here, or The Wall, or whatever, so it felt a bit like ancient history.

- Although it's changed a lot physically, do you think Abbey Road contributed anything to the album?

That's always the question I get - why do I think the record did so well? What I tend to firmly believe is that it's not for any one reason. It's a collection of elements that came together to make it work. One of those ingredients - well probably more than one - two or three - were Abbey Road, because the record is still seen as sonically really good and that was partly down to the maintenance staff here, and partly down to Alan Parsons. Without him I think it would have ended up not quite as good.

There was an enormous amount of attention (and I'm sure there still is) applied to lining the tape machines up properly, and reducing the amount of hiss and noise.

That's part of it, and Alan's engineering expertise absolutely had something to do with the success of the record.

I also believe things like Hipgnosis... Storm and Po's record sleeve was absolutely right. People sometimes ask about that - they came into the studio to show us their ideas. We saw the prism and said 'We like that'. They said 'No, no, we've got others' but we said 'No, no, we don't want to see others, we like that'!

I think Roger's lyrics are extraordinary, because I think they are as relevant, if not MORE relevant, to a fifty or sixty year old, than to a twenty-something year old.

The other thing that has to be recognised was a man called Bhaskar Menon. He was made president of Capitol Records in America. Bands always blame the record company, but we always thought Capitol had never really got the story with us, and were a bit disappointed with records that would chart higher in England than the US, and Bhaskar set out making this record number one, and he did it. He motivated the company, he did whatever was necessary to make the record work.

I think without Bhaskar, the record would have done better than the others, but certainly wouldn't have picked up the momentum it did.

- You've mentioned others, but you haven't actually mentioned the band...

I think the band were at the most creative [point]. Everyone contributed ideas, and there was just the sense of getting it done. It wasn't a complete process - we didn't spend a year in the studio - we did other things in between. We did tours, and the Pompeii film.

- How much did the band's earlier work on soundtracks influence or colour what you did on The Dark Side of the Moon?

I'm not sure. It probably paid some part, because we'd certainly got used to things like cross-fades as ways of moving from one piece of music to another. I don't remember anyone saying 'Let's do this like a movie' or anything like that, but we had learnt quite a lot about cross-fading and how to make it work, and how it sounds, and that is something I DO listen to and think we got right. Partly because it's one of those things that people assume that computers can do really well, and easily, now, and actually I think it's one of the few things that computers tend not to do very well. You set it up and it does it, but actually, it's all about what you're hearing, and maybe not fade completely, you hestitate a bit, then fade it a bit more...

- Nick was asked about the Wizard of Oz synchronicity myth...

It was a very odd occasion - we walked in [to the studio] and it wasn't Syd Barrett - there were three guys here, one of them a tin man, one of them...[laughs]

- What was the mood of the sessions like? Was it a struggle to get things done?

That's one of the things about Dark Side. The time in the studio was very productive. Funnily enough, the most difficult album ever was Wish You Were Here because we had unlimited time. With Dark Side we knew we'd only got a week to get some things done, then we were off on an American tour or whatever.

My memory is of ideas being delivered and tried and developed very quickly. Compared to three or four years before, it was extraordinary how much time we spent on Dark Side. When we were doing Piper in 1967, EMI was still run on a pretty tight session schedule, recording from 9am - 12pm, then some lunch, then maybe you did an afternoon's session...you did that day by day. It got trickier towards the end, when we were mixing, and that's why Chris Thomas was brought in, for his opinion. It's really good that we were able to say 'Let's bring in someone else to arbitrate'.

- Was there any music left over, unused?

No, we very rarely had anything left over [chuckles]. No, that might have been really great, as it might have given us a kick start on whatever happened next.

My view now is that we made a big mistake really. What we should have done, was we should have toured Dark Side for much longer, which almost certainly would have left us with a film of it, which would have been so great to have now. We have not got a record of what we did, such as the Earls Court shows where we fired the rockets up, all that sort of stuff, and it would have given us more breathing space before starting on Wish You Were Here.

- What do you think about cover versions of Dark Side?

I like Dub Side of the Moon, I like the Scissor Sisters, I like Luther Wright and the Wrongs, who covered the entirety of The Wall as a country and western album - and if you haven't checked it out, you should - my problem is with tribute bands.

Herbie Hancock did one of our songs, Eric Prydz did too, I like it when people reinterpret something. That's great. What bothers me are tribute bands who practice every stick I've ever dropped.

Everyone's entitled to perform the music; we should be flattered, and I am. I still feel that there's an element of rock music which is expressing yourself, and doing something different, and it loses that. And also, something like the rototom part in Dark Side, I've NEVER played the same way twice, I always listen to the records and think 'Oh god, I wish I'd done it differently', and continue to do so.

In fact when I did a few Dark Side shows with Roger a few years ago, I always approached it each night and think 'How shall I do it', and 'Let's try to do it better tonight'. With the tribute band thing, they just lock into the way it was done. I wouldn't mind if they changed it a bit. I'd like to hear them doing what, hopefully on a good night, we would do, pushing it into something else.

One thing I really like about the best known tribute band, the Australian Pink Floyd, is that they eventually split due to musical differences - you'd have thought that they'd have seen that coming! [laughs]

- You touched upon Storm's prism design that everyone knows and loves. Do you remember any of the rejected designs? Storm certainly doesn't, and he'd love to know! He's asked me to find out if anyone remembers!

[Laughs] Well, the good news is that none of us can remember, but without doubt they were used eventually. Storm is absolutely ruthless in having an idea and making sure someone uses it. Either it resurfaced on Wish You Were Here, or 10cc, or any one of the other bands he's worked for, he would have ended up using them elsewhere.

Nothing was ever consigned to some sort of box that was never opened again...

- You must look back over the 40 years, tinged with some sadness because it didn't get better than that moment. What happened with the group afterwards, the fall-outs, the frictions, the court cases... You must have mixed feelings about how things were then, and how they became subsequently?

Not really because I feel as though in some ways lots of things were resolved, and lots of things got done. For me, I think Wish You Were Here is still a good album. I think the tours we did after Roger left were some of the best music ever, for me, because we did a year tour, which meant you REALLY got stuck into it, and I played more than I'd ever played before, which I felt was terrific.

I eventually ended up making friends with Roger again, and we did Live 8.

And, in some ways, it's a sort of fairytale really! The only thing I regret is we're not on tour now, but then there are some car dealers who feel the same way... [laughs]

- To what extent did you develop the album as you played it live?

I can't tell you how much we developed it, but we did develop it. I think we were all so paranoid about bootlegs later that we stopped doing that. It's a great shame, as the tendency after... post-bootlegging, was that everything got done in the studio, and you'd tend to stop when you've played the thing perfectly. Whereas, when we were on the road, playing it, you'd get a reaction.

On The Run was a completely different piece originally, but that didn't seem to work particularly well in the context of it all.

It would have been great to play the whole thing beginning to end live, a number of times, and then recorded it. I think we would have sequenced it differently now, looking back on it. It's not only what you play, but where you play it that could have changed. We certainly made Eclipse, at the very end, more powerful because we played it on the road. It went from Brain Damage, to a version of Eclipse, that didn't have enough of the grandeur to the ending, I remember, specifically...

Our thanks to Nick for his time, and to all involved for arranging the event.