It's official - ZOUK!

[John Flynn]

I have always thought of the Comhaltas Ceoltóirí Éireann (CCE) "Society of the Musicians of Ireland," based in Dublin with chapters all over the world, as the authority things like this. As far as I can tell on their websites, they still call it just "bouzouki" when they talk about it all. It seems they don't deal with bouzoukis or guitars much at all.

[Beanzy]

That's because although there's crossover with players doing both, they like to focus on traditional music and tend to leave Irish folk music do its own thing.

[John Flynn]

That's because although there's crossover with players doing both, they like to focus on traditional music and tend to leave Irish folk music do its own thing.

Thanks for your response. I have a question: Where are you drawing the line between Irish traditional and folk? Just like instrument names, sub-genres can really get confusing. So my admitted non-expert understanding what's really "traditional" in Ireland is O'Carolan and other harpers and perhaps some Irish bagpipe music. But of course, that's not "Trad" which is session tunes. Then I think of Irish folk as ballads like "Danny Boy." Am I anywhere near the target?

[Beanzy]

O'Carolan is a thing unto himself really. More akin to an Irish Vivaldi in his own way, very much a part of a lineage, and his melodies are used in a lot of trad situations. But you could just as easily do an ensemble arrangement and it should still hold true to the pieces.

There's traditional singing, solo, unacompanied and often referred to as the old way or Sean Ós. This is based on the primacy of words and the singers exploration of the spaces within and between them. It is an exercise in manipulating time and uncertainty to lead the listener along with you. In a sense it tries to bind the listener to the singer and create a bond of the singer leading and the listeners following, but all are exploring the possibilities together. It is built on established building blocks of techniques and phrases and they are hung on the framework of the words used, but the interpretation and use will be the singers own. The tradition is not only Irish but a shared one with parts of Scotland too. It's an aquired taste and there's no one going to find fault if it's not a taste you can like.
There are instrumentalists who will transfer that sean ós to their playing and in a sense they sing the absent words with their instruments. Pipes are a great instrument for this and you can do it with whistles and flutes too.

Then there are airs which are also a kind of song without words, many still carry the lyric in the title but the words often don't survive.

There are also traditional work songs often sung by female singers in pairs or more, along with lulabies laments etc.

Then on the tune side you have jigs reels marches hornpipes polkas slides etc. These are the more popular understanding of traditional Irish music. Those can be played on any melody instrument to hand as long as you can get the rhythm and feel going.
However if you were going for a traditional feel you'd probably avoid accompaniment.

Irish folk is a broader thread still, incorporating a plethora of instruments and styles. It shares a huge crossover with folk from across the world and there are many players and singers who come from and continue to pursue Irish trad while being mostly folk performers. Songs like Danny Boy are more akin to the music hall repertoire you got all over Britain and Ireland, including songs like 'Dafodil Mulligan' etc. They get totally embedded into the folk repertoire and wheeld out at the drop of a hat.

The sesion is really just a chance to get together and share tunes and songs. There are all types, including song only sessions.
Trad tunes are the backbone of sessions but how much depends on where you are and what kind of session it is. The boundaries get a bit cloudy as many sessions will start off as quite folky but then move on to the trad, others will do the opposite. Heck I was at what seemed like a hardcore session, flutes fiddles and pipes and a box, which went on to dawn and they rounded it off with Supertramp " Breakfast In America " for a laugh.