Aah, are racist, but traditional jokes OK?
Is racist, but traditional slang OK?
Are racist, but traditional bedtime stories OK?
Are racist, but traditional secret society pledges OK?

Except in the special case--which may be what this question is referring to-- of singing the song as a critique to demonstrate the harmfulness or the subtle persuaciveness of the racism in the song--I don't see how this is really a question.

Repeating racist content is sharing racist ideas. Having a nice softening traditional patina on it doesn't change that.