The best singarounds are when one song leads into another, so you get a theme developing, and modulating. But it doesn't often happen for too long, because inevitably people haven't got a song ready to sing which follows on readily.

Mind, if you can stretch a point, you can argue a connection between the most unlikely songs. There are probably some peope on the Mudcat who could argue a link between any two songs at random. (Let's try it sometime...)

Going round the circle seems fairer, and if there are lots of people who don't know each other it's probably the best way. But with a sensitive person in the chair who uses their eyes and their imagination, picking out people around the room and knowing who they are, and bringing in the newcomers.

It means you can more readily have instrumentals in between the songs at the right time, and stories. It's a real skill, and a magical evening can be woven by someone with it. (But if the person running the session doesn't have these skills it can be dire, with people being left out and bored and irritated.)

I think the crucial bit of etiquette is to be listening to the other people and interested in them, rather than just waiting impatiently to "go on". It's not about giving an individual performance, it's about making a contribution to a collective activity.

And I also think that singarounds probably work best without too much in the way of instruments. It greatly increases the range of songs you can sing for one thing, because most of us know more songs to sing than we feel happy to play on the spur of the moment. Also it makes for much freer and better singing much of the time - except where we need an instrument to keep us in tune.