We were there on a Thursday night, arriving a bit late after session was already in progress. Level of playing was fairly advances, but can’t give much other detail since the musicians playing would not even make eye contact. We did manage to talk to the bouzouki player during a break and he said that the sessions were open, but the atmosphere was definitely not welcoming.
Old Ground Hotel
The sessions still go on in the OGH, Thursday, Friday, Saturday and Sunday (possibly other nights too during the summer).
The Sunday night session is the only one of which I have experience and it’s very welcoming - Anne-Marie Vaughan (fiddle) is there each week and she has either Mike Butler (button accordion) or Dympna O’Sullivan (concertina) with her, alternating, plus Michael Landers on guitar.
It can often get noisy in the bar but the music is of the highest quality. The session is open for anyone to join.
Say you read about it on thesession.org