Smallpiper - your pipes are exactly the sort of thing that I was referring to when I said that some instruments can do with "a bit of hush". On the other hand when there are six melodeons, four fiddles, two banjos, an electric bass, and a whole posse of enthusiastic bodhran players, belting out "Dingles Regatta" it's an ideal time for the non-participants to buy a drink, have a chat etc. I must say that on most of the occasions where I've heard quiet instruments drowned out, it has been other instrumentalists who have done it, rather that people talking. I recently heard a wonderful hurdy-gurdy player completely swamped by other musicians who didn't even know the french tunes that he was attempting to play. Loud conversation tends to mask out the lyrics of songs, however, much more than it does the tune and this is the reason why I consider singers sometimes need more consideration.

Incidently, I run a mixed monthly session and both the performers and the pub customers tend to listen to both songs and instrumentals. I have also run many mixed sessions at festivals etc and had very little problem with too much noise - if you can get a good mix of material people will generally listen.