What song is this?

Ok I am trying to find a song that I heard a few years ago, I remember that it might of been a rap or sung by a black guy and in the video it had an oldish lady who sung with him, she was off a t.v program I think? Maybe something about dreams? Because the part where they sung together the lyrics were something like ‘’when you have a dream, if you dont have a dream, then how you guna have a dream come true’’ I am just so curious to find out what song it was because I have that teeny bit of the song stuck in my head, I typed the lyrics in youtube but it didnt come up with anything remotely like it. I knoww I havnt given enough info to find out what song it is, but if anyone can think of anything it could be then that would be really apreciated :)

Thanks xx