It is reassuring to know that no offence was intended, but this doesn't make it acceptable. You might as well sing Nazi marching songs because they are historical, or 'because such hatred still exists"

At Ripon folk club in the '60s, Les Pope used to sing 'Fahren Gengen England'. Not because he was a Nazi or a German Nationalist - in fact Les was a very active member of the Communist Party - but because he felt that it was quite a jolly tune, and that for a room full of British kids to look it in the eye and sing along with great gusto completely defused it.

I think it's silly to be afraid of a song, per se. But it's sensible to ask why it's being sung.