Why don't the two of you make out a list each. A list of the issues you disagree with each other about.

Then we can bear that in mind, when you both express an opinion.

I'm sure you are both represent different strands of opinion in the world of traditional folk music.

Its sort of nearly interesting that you disagree with each other.   On the other hand, neither of you agree with me about anything much, but it doesn't make everything valueless that I have to say. And to me you are both GOM of folk music - I cannot conceive of either you holding an insincere or uninformed thought about folk music.

If you can get to the point where you say this my opinion , and I come at the subject from this direction. I think a harmonious and respectful dialogue could be achieved.