When to clap? This is one of the most fearsome questions for people who rarely go to classical concerts. It feels as though, if you get it wrong, someone will sneer at you. Not good.
 
At many rock concerts, you can just shout all the way through and no one will mind. There’s a peculiar behavior during the singing of jazz standards, when people clap at the moment they recognize what the song is. I’ve never gotten this — if you learn the verse to songs, you will know right away! But maybe the clapping becomes part of the magical transition from verse to chorus.

In the kind of jazz with sequences of solos, you’ll clap after each. It’s just being supportive, and the next player knows to keep it simple until his or her turn really arrives.

In opera, it seems that it’s right to clap after the end of an aria, if the notes are high enough and the singer makes them. Or you can boo, if you’re in Italy.

But here’s the point: Last Friday, in a sensational Aspen Chamber Symphony concert, enough of the audience clapped after the first movement of Prokofiev’s Third Piano Concerto that the applause gained momentum, instead of petering out into that awkward, “Oh, I guess we weren’t supposed to” feeling. Unexpectedly, the soloist, Yefim Bronfman, jumped off the bench and took a bow. Now the audience applauded in earnest.

It was a nice moment. For me, the end of that movement not only invites applause — it practically requires it. I even imagine that the composer then starts the next movement with a kind of new formality, as if acknowledging that there was bound to have been an interruption.

The reason not to clap between most movements is to recognize the overall continuity and allow the performers their focus in projecting that continuity. But if the music is structured for applause, it is more discriminating to give it than not.

This is bad news for those who want to keep the rules simple.
 
Alan Fletcher is president and CEO of the Aspen Music Festival and School.