Florence Welch explained to the Independent why she wanted to be involved in writing for the soundtrack (Source Heavy in Your Arms Songfacts). "I thought it would be something fun to do; I'd never written a song for a soundtrack before. It's an interesting exercise as a songwriter. You're thinking about it more in a visual tone and imagining a film score, which I think is really exciting.
They didn't specifically say what bit of the movie it was going to be in or anything .