The first song that came into my mind when I read this topic was the one sung by Cass Phang (if I'm not mistaken) in Dark Tales, the one with Gallen Lo (the only actor I could recall as of now) in it. Although it has been so many years since watching that series, the song still remained in me. It is truly a beautiful song, probably influenced by its opening preview, thus making the song sounds eeriely haunting as well.
Listen to it!