Back in the early 19th century, “the directors of the Paris Opera saw no reason to leave the success of their performances up to the whims of an unpredictable audience. To guarantee acclaim, they employed the services of an organized body of professional applauders, commonly known as the ‘claque.’ These claqueurs were tucked away throughout the audience, disguised as members of the public.” Why did this profession arise? Well, for roughly the same reason that professional music criticism did. – JSTOR Daily