Don't Clap Now!

An antique (2005) post from Alex Ross reminds us that the "tradition" of not applauding between movements is a very recent one:

Up until the beginning of the twentieth century, applause between movements and even during movements was the sign of a knowledgeable, appreciative audience, not of an ignorant one. The biographies of major composers are full of happy reports of what would now be seen as wildly inappropriate applause.

Recordings from the 1950s often have applause between movements, and Ross quotes conductor Pierre Monteux complaining in 1959 about the "artificial restraint" of refraining from applauding between movements. Like the still-under-copyright "Happy Birthday To You", many of our traditions are not all that traditional.