A good friend of mine passed away about 9 years ago, he was a true mentor for all my guitar playing. Before he died he had talked to me about doing a solo for a recording of his. That never happened. Last year I was listening to his old demo tapes and decided to remake that song and add the solo. I got part way though then put it on the backburner. Now i'm working on it again. The song is sounding really good and the mix is incredible and I think it is a real tribute for my friend, my gut tells me that he would be proud. His family on the other hand is upset at me saying I have no right to do this. He never had any song at studio quality until my version. He wrote the song about 6 months before his death and alot of his friends don't even know it exists. I know I don't own the song in anyway but I want to share his legacy with the world. His family aside, what are the rights associated with this? What are the limitations to making a song like this?