Ahead of his 68th birthday, we asked film composer Hans Zimmer to dissect his monumental score for 'Interstellar' (2014). Zimmer composed the film’s haunting main theme after reading just a single page of the script, a heartfelt exchange between a father and daughter, without even knowing the film’s genre. Today, it means more to people than ever before. Recorded on the organ of Temple Church by organist Roger Sayer, Zimmer explains why he chose that specific instrument for his soundtrack. | Cla