Interstellar director Christopher Nolan wouldn't tell composer Hans Zimmer what genre the film was

Director Christopher Nolan certainly gave composer Hans Zimmer a tricky job for Interstellar's soundtrack: he wouldn't tell him what genre the film was.

"It was very important to me that the music not pay any attention to the genre of the film," Nolan said, explaining that he simply asked Zimmer to come up with some ideas (presumably, of course, not telling him the name either. That'd be quite a giveaway).

"I'd give him whatever came to mind," Zimmer said, having worked blind to the fact that the 2014 film was an epic sci-fi adventure.

Along the way the composer was told the film centred on a father/son relationship and it was only after he'd created more music that Zimmer was told it was in fact a daughter.

Nolan explained this by saying he simply wanted Zimmer to create music which related "to the heart of the film".

Zimmer's early involvement in this Oscar-winning flick appears to be a break from the norm. Seemingly most films use other music while working on the early stages. But Nolan was always using Zimmer's work.

"I listened to it extensively while finishing the script and in production."

And, keen to move on from other projects they've worked on together, this film's music took them on quite the journey, including recording a church organ live.