Thanks Don. If this is the one from the Seattle Folklore Society, this is what they have on their webpage about the monthly circles:

"We're just a bunch of folks who enjoy getting together to sing -- no particular expertise required (staying in key is nice, but you won't be shot if you don't). We sing mainly folksongs (your definition thereof), but you may hear almost anything at one time or another. We have no dues or other memberships requirements, though we are associated with the Seattle Folklore Society.
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Once we get started, singing goes around the group in a circle. When your turn comes,you may choose to sing something, request a song from the group in general or from a specific person, or pass (and those--aside from those of common courtesy--are all the rules we have). We all join in on choruses and anything else we recognize. There's no official body of songs, though a lot of people bring Rise Up Singing (AKA "The Blue Book") or other songbooks. Some people accompany themselves on various instruments, some don't. "

Unless their rules have changed, it sounds like they are running a very nice community sing that is welcoming to all levels. They have set some general rules, but they do not seem to be dictating that the songs must come EXCLUSIVELY from the book.

I think Janie has given us some very good insight. It is people like Janie that really needs to be attracted and feel welcomed. From the song circles that I am familiar with, the idea of building a community of people who share an interest in song and enjoy the commmunal aspect of the event.

From the description of the Seattle Song Circle that I found on their webpage, I feel that this is a good model for most groups to follow.   Perhaps, as Don suggests, the rules have changed and they are exculsively using one book. That certainly changes the feeling - IF that is the case.   I'm not sure it is.

Sing for the song! Sing for the community. That is pure folk music, at least as close as we can get in this day and age. Partcipation, not performance!