I wonder whether Guest above who complains about 'arrogance' has ever attended a session, or been in a pub for that matter. Sessions take place in pubs because they are social gatherings (and open to all-comers which a private session in a house would not be) and because in British culture pubs are where people go to socialise. It is up to the landlord to judge his customers' reaction to the music - you can be assured he will only allow a session if he doesnn't think it will adversely affect his business.

A session will take place whether or not there is an audience. If other people in the pub wish to listen they are welcome to do so, and if they choose to ignore it then that's fine too. But even if the pub is completely empty apart from the musicians themselves, they will still play.

My regular session occupies one of several rooms in the pub. Mostly its just musicians, although sometimes a few people come in to listen. Most of the pub's customers stay in the other rooms, but seem to be happy that the music is there without wanting to come into listen to it. Most importantly, the landlord is happy to have us.