The other awkwardness thta can arise is when a newcomer has a different sense of timing about putting in new songs in an unstructured session.

What I mean is, in any session there tends to be a certain instinctive gap between one tune or song stopping and a new one coming in. Time to draw breath, and look around, and the body language shows whose going to do something next.

But you sometimes get a stranger who comes in and doesn't notice this, and noone explains because nobody thinks consciously about this kind of thing. And they either burst into a song or a tune prematurely, or when they've finished do another straight on because nobody has jumped din soon enough; or they hang back and don't give the signal they want to do something, and don't ever get in.

RC's experience sounds like she was just up against bad manners - but conceivably something like that could have come into it. If the rude fella had signalled he was going to do his thing, and was lumbering into action when you started, and he's thinking "she's nicked me spot, I won't let her do that." Still bloody rude of him though.

It all looks spontaneous and unstructured in a pub session - but in fact there's a structure there all the time. And it varies from session to session and place to place.