Iain, there is a web site, www.musicmountain.org, for this place.
I regularly attend several chamber music concerts there in the summer -
if you're ever in the area, it is a beautiful spot for music making -
a Tanglewood for chamber music.  I know the performances are taped for
broadcast but as to their availability to the general public, I am
uncertain.  An e-mail to them should certainly get you that info.

Phil Bunker