A young couple walked into a folk club in Brighton recently. No-one on the door, it is run on a collection-at-the-interval basis. Their first visit, so they had no idea of the etiquette and no-one had greeted them and explained what was going on. They walked up to the bar in an alcove and ordered a drink and carried on talking whilst they waited for their drinks to come. An experienced singer/guitarist and ex-folk club organiser was singing at the time. He continued singing but walked towards them. When he reached them, He stopped singing and said, "Not spoiling your conversation, am I?"
They did not not wait for their drinks but walked out. I would suggest that this criticism of potential audience was not a very clever move.