Keeping a chamber orchestra alive, even in a city known for its vibrant cultural scene, is a tough assignment, and this week’s announcement that Seattle’s Northwest Chamber Orchestra would fold came as a harsh dose of reality, but not a big surprise. “There was a time when the loss of the Northwest Chamber Orchestra would have been grieved much more by the music community. The impact is less now, not only because its audiences were in a downward spiral, but because there are more opportunities to hear chamber orchestra repertory now.”