Many nightclubs from this era were very loud and very dark. Plus some of the best ones were incredibly crowded. To begin with, I could seldom get back far enough to get people into frame from head to foot and when I could, people would be constantly walking in front of me all the time. Then I bought a 24-mm lens and only had to be four or five feet away.

Once I became a photographer, it stopped me being scared or intimidated by gangs of young men of whatever stripe. Initially, I could hide behind my camera but eventually I came to realize that if I was polite and friendly to them, then they probably would be to me too - a good life lesson.

When I was starting, I was very much influenced by the straight up, eyes to camera style of August Sander. He is really the only one. Had I known then the work of people like Ken Russell, Vivian Maier, Helen Levitt, and Steven Berkoff, they would undoubtedly have influenced me too.

When I gave up my office job and became a full-time professional photographer, my fortunes certainly improved markedly. We moved away from the council estate into our own house and for the first time in my life, I had a little spare money.

The reason why so many of my photographs in the book were taken in stairwells and corridors was that that was the only bit of spare space available and, in some cases, the only place where there was enough light to see anything. Even then, it was often so dark that I couldn't tell which gender my subject was (not that I particularly cared) and too dark, before the era of autofocus, to focus. I had to find a light (or carry a torch) and pre-focus.

I started out, in the mid-'70s, taking photographs of rock bands that I liked but not because I really wanted to photograph them. Initially, I was pretending to be a photographer, simply so that I could go up to the front of the crowd and be a bit closer to the bands. But, I found I was gradually developing an interest in the photos I took.

Many nightclubs from this era were very loud and very dark. Plus some of the best ones were incredibly crowded. To begin with, I could seldom get back far enough to get people into frame from head to foot and when I could, people would be constantly walking in front of me all the time. Then I bought a 24-mm lens and only had to be four or five feet away.