This has become a bigger theme than I expected, but also a training issue. Last night José Gonzales was supported by a guy who announced himself as James. He explained he had supported the artist on the US leg of his tour but this was his first time here.
He played three instrumental tunes on a 12 string with some competence although the level of conversation in the Anson Rooms was higher than his noise. Then he walked off leaving us to wait almost 45 minutes for José to come on.
Later we were told that someone had shouted 'F***ing sing'; at him which had annoyed him as he is an instrumental artist. He uses the vocal mic to communicate with the audience between tunes only.
So here's the thing. If someone in the audience annoys you, oh ye of artistic temperament, don't punish the ones who haven't annoyed you by walking off. Mrs T was knackered by a long day and the 45 minutes standing wait nearly did for her and certainly prevented her from enjoying the main act (which was brilliant - review later). And if there is something strange about your set, like an unused vocal mic, why not explain. It can only help.