"I think flicking through folders of words to decide what you're going to sing next when others are doing their bit can be a bit offputting."

Guilty as charged. Panic makes me rifle through my little binder o'songs even though I typically put a number of planned songs in the front, just so I won't do this. And yes I need the words because brain will freeze in mid song.   I do get fearful through out the session that maybe I don't know a song well enough or feel the mood isn't right for what I previously selected. I try to do my searches for another song on the sly though not always successful.

As to noise and talking and crisp munching, though I typically pay attention to performers, I like it kind of boisterous when it comes to my turn (only in sing around sessions - no floor spots for me). The busier and noisier it is the less inclined I am to panic. I feel kind of hidden in the crowd and that lends me confidence. I tend to really belt out in that "safe" environment.

Quite daunting though, when the room shuts up and people start filtering in from other rooms and from outside the pub once I start singing. This is precisely when I find I need the words.   

Moral of the story? Please go easy on us toddler and/or doddering folkies. We are learning and/or fogetting how to behave in folk settings.