In Singin' in the Rain (I know, I know, the height of realism), the big Hollywood premieres of the silent movies shown have entire orchestras, who play music that seems synched to the action on the screen. Was this accurate for such special events? Did silent movies have soundtracks recorded on phonograph that were distributed along with the film reels? Did audiences in general (not individual annoying people) feel more free to comment more loudly while the film was in progress, owing to the lack of dialogue? Or was the silence/soundtrack just as respected?
You might get a lot out of David Bordwell's work... I think the book Exporting Entertainment: America in the World Film Market 1907–1934 gets into the circumstances of watching a film, although that one's more about American movies being seen overseas.
My understanding is that while phonographs might exist for some silent movies, it was much more common for a cinema to have a musician (usually pianist), and some films were distributed with sheet music for the main themes. The musician would sort of improvise through the rest.
Silence may have been respected as much as now (which, in day-to-day reality, isn't as much as you might imagine, depending on what you're seeing where), but before the 1960s, there was less of an emphasis on showtimes. People would buy a ticket and enter the cinema and just pick up the film as it was being played, watch to the end, then watch the bit they missed from the beginning, then leave where they came in.
(The idea of viewers having to see a movie from start to finish was really a Hitchcock innovation.)
Prior to 1915-1918 or so, movies were still kind of a high-tech marvel, a technological fancy that had more to do with carnival sideshows than theatrical arts, so people treated films more like The Snake-Skinned Girl than Much Ado About Nothing.
There was a piano or organ player in the back of the theater and they had deliberate times throughout the movie when they would play for special effects. Saw it in person at the Chicago Science and Industry Museum in the 1960's.