I was sat at a campfire earlier this year and we had got one of those realey good sessions going,my old guitar was being passed around ahd various songs were being sung/played.A go-od time I played and sang a song in a ballad style with simple chords and along came somone from out side the group who loudly said you'r playing that all wrong let me show you,he was told wait until the song was finished. when he got the guitar he then tried to "tune it as it should be tuned"quite a hard thing in the dark with a twelve string, and played every thing he tried in the style of the Pouges on acid.When being asked to "let somone else have a turn"we got the you dont know good music and all that.
The upshot was people went away and the evening closed on a sour note.