Most film scores are written in a conventional way. The director or producer(s) of the film will provide the composer with a rough cut of the film (scene by scene), accompanied by brief ideas on what the director wants in terms of tone and style. Then it’s up to the composer to write something appropriate for the film’s story and context.
However, the story behind the score for Christopher Nolan’s film “Interstellar” truly is something to behold. Nolan asked Zimmer whether he would be able to write a rough score for a prospective film he had in mind, based only on a single sheet of paper. Zimmer subsequently agreed. The paper contained a very brief story of a father leaving his child behind, featuring two lines of dialogue: “I’ll come back?” and “When?” Zimmer wrote an emotion, personal film score and sent it to Nolan, who loved it.
After approving the score, Nolan revealed to Zimmer what the film would be about – a massive, epic tale of humanity and science, set in the depths of space. Zimmer was taken aback, believing his score was entirely unsuitable for the film. Nolan refused, saying the movie was inherently personal. And the rest is history.