Relevance schmelevance. Stay neutral and sing songs from both sides if they are good songs/tunes. Same goes for any song themes. As an example I usually try to sing the Blackball version of Blow The Man Down (warns against Blackball ships) together with Hoorah For The Blackball Line, (very *pro*) or Rochester Recruiting Sergeant/other recruiting songs,together with anti war songs in the same evening set, lest anyone should accuse me of bias. This makes me a middle of the road singer;-)