Folk music as entertainment or folk music as collecting and preserving history in the musical and narrative form.

As the former, racist songs are completely out in my opinion for what its worth. As the latter, you are walking a tightrope, but airbrushing bad bits out of history isn't a good thing either.

I would suggest a concert is entertainment and unless you are using song as part of a history lecture, (I have been to some fascinating concerts where the artiste is doing just that,) I'd question the logic of portraying it as entertainment. Of course, today people are writing and singing songs that portray their political views, and that is part of the folk tradition. Doesn't mean the audience have to agree with you. I rave over listening to Dick Gaughan, but think he is simplistic and misguided in most of his rants. Still love his concerts though.