If you are in Dublin on a Friday at around 9PM, and are up for a unique musical experience, go to the Teacher's Club, located in a Georgian house on Parnell Square. There they have a cozy meeting room, with a tiny bar, and chairs set up in a semi-circle. At first we thought we were in the wrong place, until a woman seated next to us rose to sing a ballad in the Sean Nos style. She was followed by another, then another. They were all part of a respected traditional a capella group called An Goilin - http://goilin.com/. We were the only tourists that night.