I had one of those moments when Kris Kristofferson opened for Blue Rodeo at the Canada day concert in Toronto we always went to every year. Totally unexpected, and it was awesome when he came back out and played a few tunes with them later on. Was great at the time, be even better looking back on it afterwards. Another one when Alan Doyle from great big sea happened to be in a club we were in while another band was playing and he got up on stage and played a few songs with them then faded back into the crowd. Wish I could remember what band it was, I'm terrible with band names and albums, but they were actually pretty good too.