
Sara F. answered 03/02/21
Experienced Carnegie Mellon University Honors Student
The practice of this "formality" within classical music became established with Richard Wagner (1813-1883). Wagner heavily believed that his operatic and musical productions were the culmination of sophistication and pure art. Not only did the composer have concert halls specifically for him, but he installed all of these formality rules in order to essentially make the audience receive the art as he wanted. Wagner was also a very religious composer and he wanted his music to be taken as seriously as those who attended Church. After Wagner's time, a lot of his practices with "audience manners" and customs stuck around to what we see as this formal, untouchable atmosphere today (including this stingy no clapping between movements).
Before Wagner, classical music was shared more casually. Just like Shakespearian theatre time, audience members were rarely quiet, still and sitting in the dark and the experience was all around more enjoyable and collaborative as a whole!
I hope this helps! I would definitely look into Wagner as well. While he was a brilliant composer, he was rather racist and an intricate fellow.