Classical Convention

Today's issue of the BBC magazine describes proper clapping etiquette:
To Clap or Not To Clap.

At a rock concert it is considered acceptable to applaud like a maniac, whoop, holler, punch the air, and even shout "rock 'n' roll" at the end of every song, should you see fit. But this is not the case in the world of classical music. You will find aficionados who sneer at "those people who clap after every movement". And the Time Out listing magazine's classical editor Jonathan Lennie has caused a minor kerfuffle in this rarefied world by going one step further and criticising those people who clap the microsecond a concert is over. In an open letter to the "Loud Clapping Man Who Sits Behind Me At Concerts", Lennie wrote: "Having sat through a long and profound work, why do you have to start making a racket as soon as you perceive it to be over?"
... He insists that for some sombre pieces, a period of dignified silence after the last note is played is essential to appreciation.

These conventions have been around for a while and as Alex Ross points out(New Yorker article) most of these conventions are bourgeois inventions. They made classical music such a class act in the middle of the 19th century. He quotes James Johnson’s “Listening in Paris,” describing a typical night at the Paris Opéra in the years before the French Revolution:

While most were in their places by the end of the first act, the continuous movement and low din of conversation never really stopped. Lackeys and young bachelors milled about in the crowded and often boisterous parterre, the floor-level pit to which only men were admitted. Princes of the blood and dukes visited among themselves in the highly visible first-row boxes. Worldly abbés chatted happily with ladies in jewels on the second level, occasionally earning indecent shouts from the parterre when their conversation turned too cordial. And lovers sought the dim heights of the third balcony—the paradise—away from the probing lorgnettes.

He further writes:

In other words, the opera served mainly as a playground for the aristocracy. The nobles often possessed considerable musical knowledge, but they refrained from paying overt attention to what the musicians were doing. Indeed, silent listening in the modern sense was deemed déclassé. Johnson quotes a nobleman writing, “There is nothing so damnable as listening to a work like a street merchant or some provincial just off the boat.”

And to think of all that clamor about clapping at the right moment.