The way I often find what I’m going to write next is by writing.

No, they are three completely different processes. In film, I try to really blank out my mind when I see the film for the first time so that I have no preconceptions. Early on in my career, I tried to do all this prep or even read the script and write music, but none of it ever survived. And I realized the best way to go at it was to be as blank as I can possibly be. When I’m writing classical music, it’s much more nerve-wracking because I’m starting with nothing! And I don’t have a picture to drive me on. I am wired now, for 38 years, that I see a moving picture, I hear music, you know what I mean? But with classical, I got nothing, and at first that was totally terrifying. But I forced myself into it, and then something develops, and it becomes very liberating. With the rock music, it’s a whole different process. I mean, I can’t do anything until I get the message.

Yeah, I think it’s a combination of all those things, really. I think narrative is significant and important to me. And I think most of the narratives that really struck me were about history or were narratives that I received in ways that were abstract, so they were kind of nonlinear narratives that I pulled from, for example, music. You know, music was a huge inspiration to me growing up, I grew up listening to a lot of reggae music, a lot of dancehall, dub. If you listen to that music, I think one of the things you realize is that those particular artists, those legendary artists who were making that music in the ’70s and ’80s, and even to some degree in the ’60s, were really good at provoking you to go on your own journey with the information that they were giving you in the music. For me, one of the things about artistic practice is not about providing some solution, but instead provoking curiosity about some things that you should find on your own and not be led to.

I don’t begin with a material. I begin with a problem. If a material can solve that problem, then I become interested in it. Sometimes it is paper, sometimes timber, sometimes carbon fibre. There are many materials we still don’t use efficiently. I think there is always room to discover new possibilities, every project presents a different problem, and I am always thinking about how to solve it more simply, with fewer materials or a better structure. I think every material has good and bad qualities. The important thing is understanding them and using them appropriately.

I can remember feeling elated after writing the first Quidditch match, which flowed out of the pen and was barely revised afterwards.

The same thing Molly Weasley saw when she let a Boggart out of the locked cabinet in ‘Order of the Phoenix’ – my loved ones, dead. If, however, you are talking about a fear that concerns only me, it would be being buried alive. I’m not sure how a Boggart would represent that; perhaps turn into a coffin around me? Urgh.

I try to start work before 9am. My writing room is probably my favourite place in the world. It’s in the garden, about a minute’s walk from the house.

I couldn’t have asked for better collaborators on the stage play than John Tiffany (director) and Jack Thorne (writer).

I cannot possibly reveal the full horror of my most embarrassing moment, but it took place in a pub in Exeter (which is a town in the south coast of England, where I went to university) in 1984 and involved a joke made by me that backfired spectacularly. The whole debacle was witnessed by my friend Pauline, who is mentioned elsewhere on this fansite (I have to keep her happy in case she TELLS).

The friends with whom I sat on graduation day have been my friends for life. They are my children’s godparents, the people to whom I’ve been able to turn in times of trouble, people who have been kind enough not to sue me when I took their names for Death Eaters.