For our own entertainment, and as part of our son's education. The nice thing about the symphony around here is that nose-bleed seats may be had fairly cheaply, with no attendant degradation of the sonic experience. If you really want to see the trombone slides move, bring binoculars. ;-)
We've seen [link|/forums/render/content/show?contentid=17479|Itzhak Perlman], the [link|/forums/render/content/show?contentid=67705|Canadian Brass], the Dave Brubeck Five (not "classical", per se, but certainly classic), the Rockettes Christmas Special, and numerous topical performances (baroque, Tchaikovsky, fairy tales, etc) put on by the Detroit Symphony Orchestra. There's also a place near us ([link|http://www.palacenet.com/index.cfm?category=8|Meadowbrook Music Festival]) that has a program called "A Night Out With The Symphony" (or something similar), which consists of an open-air amphitheatre, a big hill, and lots of happy comfortable people with kids, blankets, lawn chairs, and picnic baskets. My favorite performance there was the 1812 Overture - complete with (loud) cannons and (louder) timed fireworks.