If your really into what your doing your eyes & body language shoud provide all the smle you need - U just have to leave all the woes of daily life at the door & go for it.

Last time I consiousely watched a ceidh band member, it was because the dance wasn't gripping & I had time to watch melodeon players fingers & isten to hm - n an attempt to inspire my own playing...
I don't think he was 'smiling' but he was right n the moment & he's playng was a joy to behold - although thinking about it he did grin when he looked yup at fiddlers to judge changes etc...