4. Hans Zimmer wrote the score. (Unless it was David Julyan.)
Nolan used to work exclusively with composer David Julyan, whose scores for Following, Memento, Insomnia, and The Prestige consist mainly of moody electronica-and-strings undertones. (Julyan even worked on Nolan's 1997 short film Doodlebug.) Lately, though, Nolan seems to prefer the swooping orchestral symphonies of Hans Zimmer. Zimmer collaborated with fellow composer James Newton Howard on Batman Begins and The Dark Knight, and also crafted the Inception score, which garnered an Oscar nomination and launched a million imitation foghorns. He's now riding solo on The Dark Knight Rises and will write the score for the Nolan-produced Superman movie Man of Steel, and brought his church organs to Interstellar.