My page of links to opera companies in the region is almost complete and may never be absolutely complete. (See my extra pages in the side bar.) If you think I left any companies out, please comment here or send an e-mail to farlaf2000 at yahoo dot com. (There is also an e-mail button on my profile page.)
The list is not about who has the bigger budgets and flashier productions. It's about the number and variety of companies active in the general region -- Maryland, DC, Pennsylvania and Virginia. I've only seen productions by a few of these companies, mainly the ones around Baltimore and DC, but it's obvious that each one has something different to offer. I've read about Pittsburgh Opera, but Opera Theatre Pittsburgh is new to me, although they've been around since 1978. OTP's current season includes Bizet's "Djamileh" and Salieri's "Prima la Musica," so they're on a mission to circulate rarely performed works also. (They apparently have a special series of productions performed in unusual locations.) An opera friend told me about Opera Roanoke in Virginia. The company's artistic director is conductor Steven White, husband of soprano Elizabeth Futral (both have appeared with Baltimore Opera).
Yes, there is a Chamber Opera of Washington! The same opera friend was asking me if I'd heard about them, so I just tried a search and there they were. They're in the list now. They're planning to perform "The Turn of the Screw" in October 2009.
I'll add to the page as necessary, and I'll be working on links for my other extra page in the near future.