Liz, you disappoint me. Good beer (beer, not bloody lager!) puts hair on yer chest. An' I knows yer likes 'airy chests... ;-)

More seriously, both are important. Given folkies, I find it difficult to believe that a pub that only has shite beer will attract much attention, & that means little atmosphere. Equally, I find it difficult to believe that a pub that isn't interested in getting some decent beers in is going to be much interested in attracting folkies by running/allowing them a night!