Jim - I suspect that some of the 'joining in' that is considered to be rude in Ireland is an expression of great camaradarie in parts of England. The first time I visited the west of Ireland I made the mistake of singing along with the chorus of a song with which I was familiar with great pleasure because that is how it is done where I live. Imagine my embarrassment at finding I was the only person in the room doing so. I stopped after verse 2!

But don't condemn people for not knowing the rules instantly. Many of the singers from your neck of the woods visit England and if they don't enjoy the wonderful power of a room of sympathetic people singing with them, then they have been kind and considerate enough not to show (it in my presence), so how could I have been expected to know that they had different rules at home?. OK - NOW I know. I wait to see if other people sing the chorus before joining in, and I know not to sing along with the verses, even if I have heard the same song 10 times in a weekend. It is good discipline - it encourages respect for both the singer and the song and I'm often glad that I have listened closely, rather than joining in automatically. But when I'm singing myself in such company I very much miss having people express their enjoyment of a song by adding their voice to mine.