I have a couple of tunes under my belt now, and that makes sessions more fun, since I don't spend all of the time listening — just most of it! There are some obvious differences when you play with others, such as the fact that you have to pay attention to how other people are playing. Since I try to listen to myself and keep pace with my tapping foot, this is not entirely new ground. But when you're playing with other musicians, you can't fudge this — if you miss a note or take a long time to work out the fingering, they'll be into the next measure.
So the hardest thing for me right now when I'm playing with the session is picking up when I miss a note. I usually find myself having to wait at least until the start of the next measure and frequently longer before I can come back in, because I lose track of where I am in the piece.
One thing I've recognized is that this is essentially the same problem as breathing. As Brother Steve notes, a common way to take a breath is to drop a note. I've tried this and it's very hard for me, because it jars my rhythm. But keeping the beat while breathing is essentially the same problem for me as missing a note because I flubbed a fingering.
Ornamentation, too, presents a similar problem for me. As I noted in my last post, I'm working on learning to play tunes well without ornamentation before seriously working on adding trills and frills. But I've got Shebeg Shemore pretty much down and it really does sound better with cuts instead of tonguing in between the repeated notes, so I'd like to learn to do that. But again, the flying fingers are making it hard for me to keep time.
So my thought right now is that these problems are all related. So what to do about them? I'm not sure, but one thing which occurs to me is that I need to be stricter with myself about not letting the time slip when I'm doing my personal practice. I won't learn to do this right if the only time I ever practice it is in the couple of tunes I play at session.
I'm also thinking I should be starting to practice cuts and breathing in isolation. Maybe if the movements become as natural to me as hitting a specific note then it will be easier to avoid messing up my rhythm.