This is very interesting -I think half the battle is accepting that your voice may suit some types of music and not others- I love opera but dislike operatic stars singing contempory songs without changing their style. I have a reasonable voice for folk music and stick to traditional but I can't sing a pop song or jazz piece to save my life and so I don not try. Sean Keane sings some amazing,hauntng folk songs but I find his C & W stuff a bit of a turn off. A good voice I would probably define as one that can adapt to any style of music.