Joe Offer: "Peter and Annie will tell you exactly what Genie said, "I do not think it (Rise Up Singing) was ever meant to be that kind of 'songbook.'" They've held workshops all over the U.S. over the last twenty-five years, trying to encourage people to learn the songs, and to sing with their noses out of the book.    I've been thinking, though. The people who sing that way are in the process of learning the songs, and learning to sing together. ... Should we deny them the chance to learn these songs and to learn to sing together, just because they're not "good enough" according to our standards? Give these people a break. Maybe they're not very good singers, but at least they're trying. ... "

I agree, in part. RUS can sometimes help people (not just novice singers) learn new songs.
But over-reliance can actually impede committing a song to memory, and it often does. All too often I see people's head buried in "the book" while singing "Drunken Sailor" or "Michael, Row The Boat Ashore" or some other song that's so familiar or so simple (or both) that people who don't use the book in a sing-along would learn (or remember) it pretty soon if they weren't using the book as a crutch.

Stim said, "Music responds better to leadership than about anything else, and I don't see much reason why people who know how it's done shouldn't just stand up and do it."

I think this is a place where some group leadership could be very helpful, encouraging people to sing along by listening, watching song leader, etc., as much as possible instead of 'burying' their heads in the book.