I did my first session at the Red Deer, and the University Open Mic society were doing it on the same night. When the folk guy reminded me it was that day, I said "Wait, isn't there the Open Mic that night?", to which he replied "Is there?". So I spoke to the Open Mic lot (I'm friends with their sound guy), and said "If you're on, aren't the folk singers on as well?", to which he replied "Are they?".

They found out through me 3 days before the event, and so couldn't cancel - they've said they'd have gladly moved it if they'd known beforehand. Essentially, the Landlord didn't remember/thought it would be okay.

There were arguably more people in the pub thanks to the Open Mic, but one might think of the fact the session has been going for about 14 years first...