Anthony is absolutely right about Willie Taylor's dislike of tuning down a fiddle; the 'knicker-elastic' comment is one he used frequently.
When I'm playing duets with Andy's nsp, I always tune down. For me, I've spent a long time trying to find the right fiddle and strings so it doesn't sound like a kipper-box (or I hope it doesn't) when tuned lower. In my opinion, it's about trying to find a sound quality/timbre/call it what you will, that sounds right with the particular set of pipes you're playing with. That's the case with any two instruments playing together, of course. The only time I ever heard Joe play the fiddle was when he was about to leave my parents' house late one evening and had boxed up his pipes, only to hear the rest of us start on a tune that happened to be a favourite of his. He picked my fiddle off the top of the piano and played along till the end of the set, when Hannah decided it was definitely home time! Margaret To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html