“At first, we had a really hard time getting into the ballet world because it is very insular, and they like being secretive. Also they’re very serious about what they do, so, if you get in the way, they’re not interested. Eventually, when they realised we weren’t just making a romantic coming-of-age story set in the ballet world, but that we were actually taking one of the great ballets and turning it into a movie, they got really excited.”