The novel I'm writing involves the creation of a new ballet. If you wanted to make up a ballet based on an existing film - say, Titanic - to include in the book, would it be necessary to obtain permission from the directors to do this? The book itself is not based on the film at all, the ballet is just included in it as a minor side-story. I really never intend to even go into depth with it, but I'd rather avoid a lawsuit just in case. Thanks.