Music Banter - Help!!

I know this is a TOTAL long shot but it has been driving me nuts!! A while ago I came across a song and I don't know why I didn't write it down but now I can't for the life of me remember what it was or where I heard it!! All I can remember is that it was a slow song by a female singer and the lyrics were something about her singing to a dead friend/lover?? I'm pretty sure it is a recent song (the last few year, I would guess no more than 10 years old). I remember loving it and thinking it was very sad and beautiful and I don't know WHY I didn't download it at the time but I just thought about it the other day and now it's bugging me that I can't remember any of the words!! There wasn't a lot of background music, maybe just piano or something and I remember thinking it was haunting. Some of the lyrics MAY have been somthing like "I know you can (or can't)...??? (see me, hear me, help me??? maybe? something like this?) GRRR! So frustrating!

Anyway, if anyone can help me at all that would be great, I know I don't have a lot to go on!! I can't even remember how I came across it but I may have been searching soundtracks or something? Please help - any suggestions would be great!