In the USA, we have a gloriously excessive evening of ridiculous crap known as the Super-bowl, which seems to be a gauranteed pre-empter of Sunday music sessions at pubs. What regular events pre-empt the pub sessions in Ireland (or any other countries that you’re familiar with)?
Funerals.
Rob
Do they only have funerals on specific days of the week?
None. At least, not in the part of the Netherlands where I come from. We don’t have pub sessions. I tried (Irish) pubs in other parts of the country as well, to no avail 
Father Ted
No one plays during Father Ted. 
Ugh, in Seattle, any time the Seahawks are playing a home game, the session at Fado’s is cancelled. It makes sense from the pub owner’s view, though, the place gets flooded on those days, so he needs all the space he can get, and 10-20 non-paying musicians are a waste of his space.
Wow, Dameon, that sucks more than I could’ve imagined.
In Kerry, the All-Irelands in Gaelic football and hurling would be enough to cancel or postpone a session in certain pubs…No one wants to listen to the oul’ diddley-eye when Kerry’s in the finals…
Nothing stops in Kerry when they play hurling as they are completely useless and not many people care, football is another matter altogether.