DOWNLOAD THIS NOW: Karen O, “The Moon Song”

See how Joaquin Phoenix is staring outside his window in the Her still above? That pretty much nails the lonesome troubadour feel of the exclusive song Karen O contributed to Spike Jonze’s latest film. In case you haven’t heard, it’s about how Phoenix’s newly single character falls for a Siri-like personal assistant that happens to sound like Scarlett Johansson.

Check out the trailer below, although the movie won’t be receiving a wide release until early next year. In the meantime, “The Moon Song” will be available gratis until it hits 10,000 downloads on Warner Bros.’ Soundcloud account.