I still don't understand, Dave. If I'm a dancer, I don't care if the band stand, sit or lie down as long as the music and the caller are good. I've seen sitting and standing from guitarists, bass players, players, accordionists, melodion players and even callers (though in the case of the sitting caller he was recovering from an operation, admittedly). Did I even give it a second thought? No. It never crossed my mind to question the judgement of the musicians.

If I'm a musician, I adopt the posture that best helps me play. I have seen (and been in) bands with a mixture of sitting and standing, all standing and, in one case only, all sitting. Again, it never crossed my mind to question the judgement of the musicians. If I'm in a band where the leader insists I sit if I am happier standing to play or vice versa, I conclude this person isn't interested in the quality of the music and join another band. Not that I have ever heard that this has happened. I don't know of anyone who has ever brought this up until I read this thread.