"As a singer I don't actually think there's much wrong with subtly adapting a song to suit your audience and the current context - it's just when someone else comes along and draws sociological conclusions about past history from a version subject to clandestine modern alterations that we start to get into tricky territory - as some of Nerd's own research illustrates very well."

I couldn't agree more, Brian - perhaps these thoughts should be referenced the next time someone starts a "Why do we need to research folk songs - can't we just sing them?" thread.