Yeah Yeah Yeah's frontwoman Karen 'O' Orzolek wrote this lullaby for the 2013 feature film Her, with the movie's director (and her ex) Spike Jonze. She recalled: "'The Moon Song' was written and recorded in the most humble of circumstances; at my dining room table, a few paces away from the couch [where] I read the script for Her for the first time."
This marked Orzolek's second film collaboration with Spike Jonze, after she wrote the soundtrack for his 2009 film Where the Wild Things Are. The pair also previously collaborated on a 2005 Adidas commercial, Hello Tomorrow.
Orzolek recorded a second version of the tune with Vampire Weekend's Ezra Koenig, which was included in a three-song EP of "The Moon Song." "I wrote the song as a duet," the Yeah Yeah Yeahs singer told Rolling Stone. "I was really excited at the prospect of getting to record it with a male vocalist. Ezra was super cool and open, he slipped into character like a champ and damn he's got the goods.... Singing this song with Ezra felt like fulfilling a wish of my diehard romantic junior high self."
This heartbreaking tune was written by Arcade Fire's Will Butler (brother of frontman Win) and frequent collaborator Owen Pallett for the score of the movie, Her. It was performed by the whole band. Butler told Billboard magazine that the score changed "radically," when Scarlett Johansson replaced Samantha Morton at the last minute. He explained: "The movie got less high-concept and became more about these two people. The music did the same thing: It started in a Blade Runner world and slowly became more piano-centric and less epic, with strings and warm synthesizers."