It's a beautiful, ethereal song that perfectly captures the film's dark and magical tone.
However, there were also other songs used in the movie's promotional materials and soundtrack.
To be sure, could you please provide more details about the commercial or song you're remembering? For example:
* What is the specific scene or event in the commercial?
* What are the lyrics you recall?
* What is the general mood of the song (e.g., uplifting, haunting)?
With a bit more information, I can help you identify the exact song you're looking for!