I'm going to the symphony tonight for the first time since I saw Schoenberg. It's a long Berlioz piece (is Berlioz the inspiration for the character Berlioz in Master and Margarita?).
My two favorite moments at the symphony are first, of course, when the oboe tunes the orchestra, but second, it is the chorus of coughing that follows the end of a movement. I know that yawning has been shown to be contagious, but only in very special circumstances does coughing seem to pass from person to person. In the symphony, it's the realization that you need to get all the coughing done before the next movement that sets you off, it's not some deep, underlying subconscious thought process.
On a related note, sometimes when I'm watching baseball games on mlb.tv they won't show commercials, they'll keep a camera on the broadcasters (who do not seem to realize they're being filmed). Throughout the commercial break, many announcers make all sorts of funny noises, including lots of coughing, I guess to keep their voices ready to go. Unfortunately I've never caught them bantering inappropriately.