I just remembered, too, another booing incident in addition to the John Cage one. Years ago someone yelled out a loud “boo”. And it was an orchestra member. On stage. (I happen to know who it was, but I’ll never divulge that information.) It was someone that most people wouldn’t have expected to do such a thing, but the maestro at that concert had misbehaved so badly that the musician simply let go with the opinion most of us wished we had the guts to express. I don’t know that the audience heard the boo, though; they may have been to busy with their applause.
I can’t even remember what we played that night. I only remember the maestro not being a maestro, and this one very loud “boo” coming from the stage.
(One final opera to go. I made a “boo-boo” tonight, although I’m not sure anyone noticed besides yours truly. So I guess I should boo myself.)