Last night I was talking with a friend about the mix of amateur and professional musicians at a festival. He said that he had heard rumours at a particular festival that professional musicians didn't like to see amateur musicians on the stage at a festival as it represented a spot that was not filled by a professional. He is an amateur (or a real folkie?) I guess as he hasn't quit his day job. I was surprised by this view and now I want more information from people who have been involved with festivals, organizing and/or playing at a professional or amateur level. What do Mudcatter's think and what have they heard and experienced on this?