The following was picked up recently in a session obviously reflecting someone's personal experience of some sessions...
Offered with the usual common-sense, PC-aware, non-prejudicial, con-confrontational, blah blah... because it's interesting and thought-provoking. Might even be worthy of a self-referential cautionary tale?
Anyway, offered to all for what it's worth.
1 Play as loudly and as fast as you can all the time.
2 If someone new to the session ventures to start a common tune that everyone knows pefectly well (Kesh Jig, Planxty Irwin, Harvest Home, etc) just stare at them blankly and don't join in. This is a good time to talk loudly, walk away, or tune your instrument.
3 Don't play anyything with a consistent tempo. Always play the easy bits fast and the awkward bits slowly. Try not to listen to the steady tempo the others around you are trying to maintain. In fact, don't listen to anything anyone else is playing, there is no point in letting them distract you.
4 If someone starts a tune you know, see if you can take it over and increase the speed just enough that they can't manage to play the next tune they had in mind. This will give you a good chance to jump in with the one you would rather have played in the first place.
5 If someone tries to start a tune they are a little unsure about, or are a bit nervous and wobbly, be sure to enquire loudly as to whether they shouldn't be playing it in 6/8 (if it's a jig), or say something helpful like "what the **** is that? It doesn't sound like anything I've heard before!" or "He's making it up as he goes along!".
6 When you decide it's your turn to play, just jump on in and see how many tunes you can run together into a massive set, preferably using one tune from each set you know the others will want to play. Don't stop until you feel like sipping a drink, going to the bog, or everyone has left the table.
7 Try to catch the flute player's eye and gurn at them till they laugh, it does wonders for their ability to play the thing.
8 Guitarists, if your chords don't seem right for the tune, don't give up! Keep going and going. Play those three chords louder and louder. Feel free to put your own interpretation on the rhythm while randomly varying the chords. If one or more strings are out of tune, don't worry, discordancy is an important element of Irish music.
9 Feel free to talk loudly when you don't know the tune. If the person at the far side of the table can't hear you, shouting is fine.
10 There are just not enough Bones, Spoons, Rasps, Triangles, Shaky Things, Tambourines, Kazoos, Didges, Slide Whistles, Crumhorns, Saxophones, Euphoniums, Trombones, Casio Keyboards, Indian Bamboo Flutes in the key of xFlat Minor, and Practice Chanters at sessions. Bring them in and run those Flutes, Whistles, Fiddles, Boxes and Banjos out of there.
11 The rules might vary from night to night depending on who, if anyone, shows up. And for those music lovers at the next table...
Be sure to extend the same courtesy to singers as you would to players of instruments by shouting and roaring with hysterical laughter all the time they are singing.
And don't keep all that lovely cigar smoke to yourselves, blow some over the people playing so they all get the benefit.
Hope you all find it though-provoking.