I think I'd also go along with the majority and say that in most cases a singaround works best if someone is organising it discreetly. All the postings so far seem to have only considered the performers'
side of the story though.

In many cases there is also an audience or considerable number of non-performers. I think that it is up to the person(s) organising to sometimes try and arrange the order of performers to make it interesting for them. If you have a few weaker performers, try to intersperse them with the stronger ones - so many times I've heard a whole group of poorer performers one after another (because they're sitting togther) and watched the audience dwindle away until by the time it gets round to the better singers, there's virtually no-one left. The same thing goes for type of material and even the sex of the singers. Remember also that most of the performers are audience for most of the time and that a varied program is much more likely to keep them around.

Singarounds and sessions are often a window into the folk scene for many of the general public and if we want to improve their conception of folk music, we have to take them into consideration. Most singarounds (in the UK at least) take place in pubs, and the landlord wants to feel that you're entertaining his regular clientele as well as yourselves.