Thanks, Susanne! I'll look her up.I also like what you say about "an appropriate intro." I love the song "Two Magicians" (the version I'm familiar with is the Steeleye Span one), but it requires an intro because of the reference to the "coal-black smith" -- if you don't understand the background it sounds like it's degrading persons of colour. But the real reason she doesn't like him for being coal-black is much simpler and more easily defensible -- he's not a black guy she hates for being black, but a white guy who NEVER TAKES A BATH! Once you explain that, the song no longer puts sensitive people on edge and the humor of it is more easily swallowed.
Other songs really are written from a discriminatory POV, however, and the introduction would have to reflect that.
I'm definitely against bowdlerization in all forms, however. "Those who do not remember the past are doomed to repeat it."