This scene was meant to illicit the feeling of a dream... with childlike innocence and wonder. A simple and poignant moment, given the later significance of this relationship. I chose piano here because of the music-box nature of the scene, which gives it a dream-like ambience.
An inspired Oriel woos Eva. I used the environment here to augment the sound. The tunnel itself creates a reverberant atmosphere: I used the passing traffic as a percussive loop. The constant lights provided a stage for Oriel which I allude to with a constant string chord. The piano represents his movements while the guitar slap emphasises the connection to the ground both in terms of character and location. I wrote the music before the scene was shot so the actors had something to rehearse to, then I reedited the music after to fit the final cut.
Eva's disorientation after receiving terrible news opens the film. A detachment from the world was what I wanted to emphasise. It introduces Eva's instrument as the piano and Oriel's as the guitar, interwoven with the sound of numbing disorientation which I represent with static.