Joining a session in the Willie Clancy festival

A small rant. I mentioned this to a few fellow musicians this week and they were disgusted. So anyway I went downstairs in Hillary’s early in the day on Monday. Just to be polite I asked could I join the session. I play guitar and sing. They looked at me with distain and sad looks on their faces. One of the lads said they already have a backing musician Ohhh. I said thanks very much and went on my way. Then I started thinking and I went downstairs again and told them I was sitting in with them as they were now joined by other musicians. They looked at me sadly again. I played along with them and then when I got an opportunity I sang a song. The crowd loved it but the musicians didn’t join in. I’ve never experienced this before in this great festival. I don’t ask anymore cause it’s all open sessions. What are your thoughts 😁