Concert-goers new to the classical scene are always asking, “when can I clap?” In pondering an answer to this question, I came across some interesting facts and trends on various websites of symphony orchestras and record companies, and even some discrepancies as to the basis for the tradition. One source claims that the idea of saving applause for after the final movement of a piece is actually a pretty recent (only the last 50 years or so) phenomenon, while another says that the protocol is firmly rooted in the German tradition, dating back to Mozart's time.
How you might react at a concert should not be something to stress over. It's not your fault that composers wrote works in such a way as to “fake you out,” with false endings only a third of the way through a work. The tendency worldwide is to favor between-movement applause, especially after big endings where it is hard not to applaud, but not as an obligation after every single movement, regardless of its level of finality. After a movement that ends quietly, it is preferred that there be no applause, as the silence between movements here serves as a tension builder. When an entire work ends quietly, it is extremely jarring when one or maybe two attendees clap before the final note has even faded away. When this happens, the applauders, or shouters of “Bravo,” become performers, proving to all that they know when the work is over. (Or perhaps that they are following along in a score to the work). There are no awards for being the first person to clap; if there is any doubt, it's ok to be a follower and not a leader; the conductor will put down his baton and turn around and bow. I feel safe in quoting Billy Joel here; “Leave a tender moment alone.” Like most musicians, I cherish that span of silence that lay between the final placid note and the first pair of clapping hands. In any case, if someone's applause bothers you at a concert, it is NOT ok to express your dismay by giving them the hairy eyeball.
Let's look at some other questions that surface from time to time. I have used the terms “movement,” “piece,” and “work” above, but never the word “song.” To hear iTunes tell the story, everything that has sound is a “song,” whether it is a 5-hour Wagner Opera, a Bach cantata, or one of those little 20-second snippets of song on the Beatles' Let It Be album (like Dig It). Sure, iTunes, whatever. The concert hall reality is that classical composers write works (think “work of art”) or pieces, which may have several sections or movements. They may write song cycles, literally an album of songs, but that album as a body is referred to as a piece or a work.
Confusion happens when there are differing styles and tempi within an individual movement. Prokofiev did this a lot. It can also happen when two movements are linked together. (Musicians call this practice attacca, Italian for “attached”). In my first season here, maestro Kirk Trevor conducted Brahms 4th Symphony with the final two movements linked very seamlessly, and when the Thursday night performance was over, (thinking the third movement was actually 16 minutes long), no one clapped! He had to step off of the podium and bow to convince the audience that there was not another movement forthcoming. The Friday night show utilized a somewhat longer pause between the third and fourth movements.
I think we can all agree that, applause or not, there is no worse interrupter of a classical concert than a cell phone going off. We depend on the audience to be sticklers for silencing their phones, and for not answering them (but silencing them discreetly) if they do ring. I refer you to a scene in the 2000 Woody Allen film, Small Time Crooks, wherein Tracey Ullman answers a cellphone call in the middle of a cello recital. It's a ridiculously funny social commentary, brought off as only Woody can.
My words here are by no means the gospel on this subject. Here are a couple webpages whose content I found useful. NeoClassical is a blog by Holly Mulcahy, concertmaster of the Chattanooga Symphony. I especially liked that she had advice for experienced concert-goers and newbies alike, with some special guidelines for conductors. And this Colorado Public Radio story gives some historical background to the differing customs regarding this issue.