I would just like to clarify my comment about the 'freebies'.
I go to various song sessions around the country and the landlords treat the participants differently in what they provide.
Some just don't provide anything, fair enough, some provide food e.g. a plate of sandwiches etc., some provide a pitcher of beer to be passed around the participants and some provide free beer etc. for the organiser.

I think that it is in the nature of sessions that it's everyone's contribution that makes a session. It's not just the organiser, and most of the time the session would/could still take place if the organiser wasn't there i.e. no-one is indispensable - what happens if they can't make it at the last minute, the session still runs.

I see this as a gesture of appreciation from the landlord to the participants and if you're on a diet you don't have to eat/drink anything!