First let me say that no one is going to have "all the tunes". There are a lot of tunes, hundreds upon hundreds of them, and a sizeable core group of these tunes will be known in common to a lot of people, but some tunes may not be known to a group, or are newly composed. Hell, we sometimes don't even have the same names for them! I lost a gig once because I thought I didn't know the tune being asked after by a certain name, although in retrospect I found I knew the tune very well, but by another name. It gets complicated sometimes. That said:
I suppose it depends on whose session it is. Some sessions are very welcoming, and some press for quality control. The best etiquette lies with the player in question: When you're at an unfamiliar session in an unfamiliar town, it's best to ask permission to sit in. That given, here in the Twin Cities such a player would be considered maybe intermediate level, but still be welcomed so long as they're pleasant, are there to contribute as best they can, and are trying to up their level. And the clunkiness isn't going to be that much an issue, because almost everyone else is playing along, too. If you have enough good players on hand, group playing masks a lot of offenses.rykirk wrote:... but was still a stiff or clunky player? I'm sure there are lots of those out there, memorizing 16 bars isn't too hard afterall. The end result would be about the same, no? What's the etiquette for dealing with that?
Session quality isn't necessarily higher than stage acts (nor are stage acts necessarily all that good); they're simply marked by the standard traditional ethos of Trad sessions, which is to string a number of tunes together, without a break, for a set the group can play. That's the fundamental feature. It can be a highwire act sometimes, and that's why communities will have their pet pre-arranged sets. Sometimes there are hiccups in the course of trying it on the fly, and then everyone cracks up. It's part of the craic. A couple of times I've started sets that I thought should be okay, but one tune would be, unintentionally, known to none present but me. What to do? I'd stop and apologize, but often in those situations the others are likely to say, "No, keep playing so we can learn it." So you do.
It's not all ensemble playing; the occasional singer or solo party piece happens now and then, but those are usually best left for when the session's winding down.