Applause (Latin applaudere, to strike upon, clap) is primarily the expression of approval by the act of clapping, or striking the palms of the hands together, in order to create noise. Audiences are usually expected to applaud after a performance, such as a musical concert, speech, or play. In most western countries, audience members clap their hands at random to produce a constant noise; however, it tends to synchronize naturally to a weak degree. As a form of mass nonverbal communication, it is a simple indicator of the average relative opinion of the entire group; the louder and longer the noise, the stronger the sign of approval.
The ancient Romans had a set ritual of applause for public performances, expressing degrees of approval: snapping the finger and thumb, clapping with the flat or hollow palm, waving the flap of the toga, for which the emperor Aurelian substituted handkerchiefs (orarium) that he had distributed to the Roman people. In Roman theatre, at the close of the play, the chief actor called out "Valete et plaudite!", and the audience, guided by an unofficial choregus, chanted their applause antiphonally. This was often organized and paid for.
Similarly, a claque (French for "clapping") was an organized body of professional applauders in French theatres and opera houses who were paid by the performer(s) to create the illusion of an increased level of approval by the audience.
With the proliferation of Christianity, customs of the theatre were adopted by the churches. Eusebius says that Paul of Samosata encouraged the congregation to applaud his preaching by waving linen cloths (οθοναις), and in the 4th and 5th centuries applause of the rhetoric of popular preachers had become an established custom. Applause in church eventually fell out of fashion, however, and, partly by the influence of the quasi-religious atmosphere of the Wagner performances at Bayreuth, the reverential spirit that inspired this soon extended back to the theatre and the concert hall.
Indiscriminate applause is widely considered a violation of classical music concert etiquette: Applause is discouraged between sections of a work, reserved instead for the end of the entire symphony. There have been a number of attempts to further restrict applause in various circumstances, e.g., court theaters in Berlin prohibit applause during the performance and before the curtain call (although elsewhere in Germany this is felt to be beyond public tastes).
On some occasions, applause occurs in the middle of an event. The President of the United States, in his State of the Union address, is often interrupted by applause; tracking the number of such interruptions has become a trend on various television news channels. It is often customary for jazz performers to receive applause in the middle of a tune, after completing an improvisational solo. Applause during a symphony is regarded as a breach of concert etiquette—any soloists are usually acknowledged at the end by standing up at the request of the orchestral conductor—but this is not always the case in opera.
Extended applause at the conclusion of an event, usually but not always resulting in a standing ovation, implies approval above and beyond ordinary measure, and compels the performer to return in acknowledgement and at times proceed to an encore.
A golf clap is a form of quiet clapping, so-named because it is the preferred form of applause for golfers; louder forms of applause are discouraged at golf tournaments so as not to disturb other golfers, who may be in the process of attempting a shot.
Deaf people applaud by waving their hands in the air, as it has a greater visual impact than clapping the hands together.
Likewise, string musicians of an orchestra usually applaud by bobbing their bows in the air or gently tapping them on their instruments' strings.
A recent phenomenon in Britain is the use of a minute's applause to indicate respect for a recently deceased person, which has come to replace the traditional minute's silence, especially at soccer matches.
A notable occurrence of a slow handclap took place during a speech made by British Prime Minister Tony Blair on 7 June 2000, when he was heckled and slow-handclapped by members of the Women's Institute. (video)
Another type of "slow handclap" is used as a dramatic device, often forming the conclusion of dramatic turning points in popular films. After some dramatic speech, one audience member claps slowly, then another, and then a few more, until the trickle of clapping gives way to a roaring applause, often ending in a standing ovation. This is also referred to as a crescendo applause, named for the increasing level of volume it produces.
During musical events it is common for an audience to clap to the rhythm of the song, to cheer the artists present on stage. Sometimes it is the artists themselves who invite the audience members to clap along. There are even songs which incorporate this kind of sound in the rhythm section, like Boston's "More Than a Feeling" and Queen's "We Will Rock You".
In some Latino and Hispanic cultures (e.g., Mexico, Spain, and some Central American countries), and also in many other European countries, a synchronized, slow handclap at the end of a musical performance signals the audience's desire for an encore.