The designer for the new production of ‘Peter Grimes’ at the Royal Opera House is John MacFarlane. He is a painter as well as a designer so, in some ways, his sets are like the original ones – lots of painted weather on a back screen. However, stage machinery is a great deal more powerful now than it was in 1945 and John can tilt the stage at extraordinary angles: 30°, 45°, even 75°. The whole stage picture is made up of huge walls, slopes and screens in swirling grey and black. There is a splash of red in the party scene but, as it happens just before the Man Hunt, you have to decide for yourself whether it's a festive colour or whether it perhaps signifies blood.

Designers and directors work very closely together on an opera. For ‘Peter Grimes’, John MacFarlane and Willy Decker spent two days listening to the music, reading the libretto (words) and throwing ideas about. Then John went away for a couple of weeks to think about the show. He made a model of the stage – just a box – and when he and Willy met again, they started to ask each other some very basic questions. Did they want a sloping stage? Did the show need furniture? What sort of colours should they use? John kept dashing off to paint little skies for the model box, or cut out bits of cardboard for the scenery, and by the end of six days he had produced a rough model of the set. After this things got more technical. John sat down with all the measurements of the theatre – the stage space, the size of the wings, the backstage areas, even the size of the dock door (the door at the back of the theatre through which the scenery is delivered) – and made sure his set would fit. Then he made a proper model, using a ratio of 1:25 to the final set, and very exact indeed. The stage carpenters would use this to make the scenery from.

All through this time he talked things through with the technical staff and the lighting designer, Max Keller. The technical crew had to work out how they were going to raise and lower the floor and Max had to make a lighting plan. It can't have been easy as the sides of the set completely boxed in the opera – so he couldn't use side lights – and the back screen was so near the back wall he couldn't put lights along the back either.

John MacFarlane, in an interview about the opera, said that, interestingly enough, ‘Peter Grimes’ is too well known. We all know it's set in Aldeburgh and most of us know, or can guess, what Aldeburgh looks like: a rather pretty huddle of fishermens' cottage on a flat pebbly beach. He was delighted when he heard that Willy Decker was going to direct it as, being German, he wasn't bothered about the precise English feel of the piece. What Willy wanted was a small town; an enclosed community looking for somebody to pick on.

Both men agreed that the opera needed the sea, but not handled in the traditional way. As John said, "The chorus are always singing about the sea, but it's usually painted behind them." He wanted to get the feeling that the sea was all around. He's done this for the ROH production by painting that peculiar sky you get at the seaside: very wide, cold and bright. After the sea, the next problem is the chorus. The chorus have an enormous part in Grimes and they demand lots of space. John decided to place them in large blocks against the sky and the walls so that they could loom up on the soloists and their compact, menacing, personality could make its presence felt.

This production was originally made for the opera house in Brussels. There they built the set, ran the opera for 10 days, and then took it down. One of the extra problems for John and the technical staff for the London run is that the Royal Opera House doesn't work like that: this house has several operas going at the same time. So that, once the crew has set the ‘Peter Grimes’ walls, got in the hydraulic lifts, tilted the floor, lit the stage and run the show, they've got to take it all down again for a performance of 'Carmen' the next night.