Uncle Jacques, I've been thinking about your comment about politics. If you want to know the politics of any particular song or tune, ask here and someone's bound to know.
But in general, unless you get a really rude crowd, if you introduce songs by saying "I hope there's nothing political about this: I just think it's a really good tune/song/whatever" people will usually listen appreciatively.
Besides, quite political people often know and sing the music of the "other side" here.
The main thing is to let people know (sane people, that is) that you're not deliberately giving offence.