We often observe the challenge with open jams, that ANYONE can show up. But last Sat we had the OPPOSITE of that, when Robbie Fulks showed up to play. He was every bit of the pro you'd expect, and as nice a guy in person as he comes across as. I don't think the majority of folk knew who he was. Hope he shows up again, but at our earlier, smaller session... The one WITHOUT accordions! 
What are your stories about when a pro showed up at an open jam you were at? Or maybe a festival? Ever play with someone and only LATER learn who it was?
What are your stories about when a pro showed up at an open jam you were at? Or maybe a festival? Ever play with someone and only LATER learn who it was?