I think what Mary is referring to is Rise Up Singing (right, Mary?).

Right from the very beginning (my very beginning as a singer of folk songs), the unspoken rule, which everyone followed, was "know a song before you try to sing it in front of anybody else." Learn it first. That's kind of basic. If you don't know the song yet, don't try to sing it. If you want other people to sing a song you do know along with you, teach it to them. But--bringing a songbook to a hoot or a songfest and singing from it was regarded as a form of cheating. A real no-no!

At the John Dwyer memorial meeting of the Seattle Song Circle (about 125 people, I think) pretty much everyone sang, and no one used a song book. The last event of the evening was dismembering a copy of Rise Up Singing and feeding its pages into a shredder as an acknowledgement and a tribute to John Dwyer's loathing of "the Blue Book" and the way it dominated some of the Seattle Song Circle meetings. He wanted people to learn the songs. John only sang songs he knew. But he knew a lot of songs.

Don Firth