The comedy club routines seen in the show, according to one WWW page I read the other day, were not filmed in the same place where the show was filmed; they were filmed at a real "comedy club."

I saw a photo of the filming being done in Jerry's apartment, and there were 2 or 3 Panavision cameras recording this ... this was supposedly done in front of a live audience, sort of like how I Love Lucy was done in the 1950s, I think. As mentioned elsewhere, I find the laughter in the comedy club to be really phony compared with that in the show, especially with these shots of the audience members all smiling and chuckling.

There was at least one instance of the comedy club routines being interrupted in a way which was sort of like "breaking the fourth wall," where this guy who was in one of the actual episodes showed up in the club and started heckling Seinfeld.

But I still don't understand how they did scenes in multiple locations, i.e., first in Jerry's apartment, then in the hallway outside the apartment, then in the restaurant, etc. Did the audience have to sit still or did they move around the studio to see the other locations? Or were the scenes in the other locations shown on monitors? This obviously happened on the shows which were in a parking garage or on the subway.

There are numerous books written about the show, I'm sure this is discussed somewhere. Exact information about this on the Internet seems kind of scarce.