"I hate for us to get too squeamish about language and songs that are now considered to be racist. I think these need to be sung pretty much as written in the context of historical presentations"

I don't see why they need to be sung at all, even in the context of historical presentations.

You can just read the lyrics, or show them on a screen. I don't think there's any need to sing them - what does that gain anyone? We all have the power to imagine what hearing them sung might have been like, hearing them sung is gratuitous.

I would leave it to those directly affected by such lyrics (ie black people) to decide whether singing them is worthwhile in terms of adding to our understanding of their impact. No white person should be doing so IMO.

As your further anecdote suggests, people may even find the reading (rather than singing) of lyrics to be offensive too. You would have to make a case by case decision based on the context.

Personally I think someone who voluntarily elected to attend a discussion about racist songs is being unreasonable in complaining about them being quoted - it is impossible to address them otherwise but I still wouldn't dismiss that complaint without giving it some consideration. How would that person have felt about reading the words on a screen, for instance?