I don't recall whether I was at the early show or the later one.  I don't recall with whom I attended, but I think it was Eddie Steiner or Mike Meeks.  I DO recall that Berry broke a string but kept going; then he broke a second string so he had to stop to restring--while Whitekeys became the show for a few minutes, and 'Keys played admirably.  Once restrung, Berry non-verbally indicated that we should appreciate Whitekeys' stepping up, as it were, and boy did we.  We gave him a rousing round of applause.  

Those days, I also enjoyed 'Keys at Chilkoots, where he played The Mt. McKinley Rock Opera that included lyrics such as, "I can take a douche or I can take a crap in my full-race Winnebago," and "We're big game hunters.  We got trigger fingers and we're feared everywhere we go.  We talk about love and we talk about life as we drag a dead moose thru the snow."