Each venue seems to have its own way of doing things, and even tho they're called "open mic" nights, many are more like sessions, with regular participants. Some that are truly "open" can have performers that - well, let's just say they're not ready to perform in public. Even the best had a "first time". A good accompanist (sp?) is a boon in such cases, and might even be on the payroll. I think it's absolutely necessary to have places for people to "get their feet wet", but that needs to be balanced with the wants of the audience. After all, it's their beer money that makes it possible.