I was just in Shetland at the end of June. Trad music seemed to be rather spotty in the hinterlands, and tourist info didn't know a lot about it. I saw posters for barn dances and whatnot when I got out to the areas that were having them.

But in Lerwick, I had very good luck at the Douglas Arms. They have a session, posted and advertised as such, on Tuesday nights. The night I was there, the bar crowd was very thin - too bad considering the two fiddlers in attendance were absolutely EXCELLENT! They were really sawing up a storm, and it was a pleasure to be there. There were 3 other accompanying musicians, and I'm sorry to say I can remember nothing about them, blinded by the brilliant fiddling as I was! There were no songs, whatsoever. It was a strictly tune session.
Good luck and have fun!

Barbara