I agree with John! In our session, we have vocal, and instrumental pieces. And some people memorize, others use sheets. What difference does it make? I have noticed that as the evening gets late, the predominate singers switch to instrumental, and the predominate melody players tend to switch to songs.....gives everyone a break and some variety. Of course, you have to be pretty ridgid about the "take a turn in the circle rule." But that works for us.