I went to the Reely Grim night at Rothwell one night when a band I was playing in, were preparing to do a ceilidh. I was looking to collect a few tunes that worked well with specific dances. Unfortunately there were 10 people there only, 8 of which were doing the dances, (I think most were there for the dancing although there was perhaps a couple of musicians within the group,) and one whistle player...the evening ended up with myself and the whistle player playing through a few tunes , (I think they had a tune book, whilst the others danced. i guess I picked a night that was very quiet, perhaps.
My problem is not playing the tunes, really, I can read music and can also play by ear but of course, playing by ear usually requires you to know how the tune goes, well enough to play it. It was more the feeling of not being involved and almost feeling unwelcome when i went to a few sessions. By the sound of it, I should try going to a few different ones as they are maybe all very different.