I and a mate 'run' a session in Sidmouth - We DONT get told what to do , but we DO get a drink , encourage people to join in and fill any gaps . !'ve been to Will Fly's session and its a good one and arrogant he is NOT .
IMHO the most important think if you are a player is to LISTEN - Who so ever STARTS the tune/song sets the key AND the tempo , and if you don't like the way its going , leave it be and do it your way later !