Anyway Jack, what did Aly Bain get barred for? C'mon, a bit of scandal...

But on the subject. I think quite a few session players (myself included) have a bit of a phobia about performance which is subsumed into the relative anonymity of a session. Other musicians are an educated audience who know what you are trying to do, even when it doesn't exactly come off. At least in some sessions, applause is not really encouraged, except when someone has done an obvious party- piece. As one player said "Don't clap, just throw money", which come to think of it ought to be the NHS's motto.

The players are just setting the atmosphere, like Haydn's at Schloss Esterházy receptions - hey, are we bigheaded or what...

In which context, I see no less than Goethe described chamber music as "four rational people conversing". Which makes a session more like "15 nutters squabbling".