The song is by a woman. The video is animated (not cartoon like, more like a camera filter) and the woman at one point is on a subway/train and singing. It's an older song and I think it was about love & kind of melancholy.

I know that's not much to go on, but it's been a while since I've seen the video and the tune of the song (not the words unfortunately) got stuck in my head. So if you could help me, I'd be really grateful.