Mister Kitzel wrote:To me the best shows are generally post WW II. Writers and directors had learned what worked best by that time. In Sunday Nights At Seven it was mentioned that Jack and his crew had to learn the difference between what made the live audience laugh and what would make a radio audience laugh. While it was a combination of everyone's efforts, I would put a lot of credit on the writers who were writing for that radio audience.
Something that changed during the 40's was the way a stand alone performer would be presented on a show. Think about Eddie Cantor or Fibber McGee. Quite often the star of the show was stationary (in a sense) while a parade of schtick comedians would come along and do a minute or two. Later the shows changed so that the star would go places and then run into the the characters. Sometimes those characters would stay for the rest of the episode. Of course there are examples of this in the 30's, but it was less common. Overall the shows moved from a vaudeville approach to a movie, or story based, approach.
We can see some of that with Jack's show which by the Jell-o years had evolved to a format where each member of the gang comes in to talk to Jack and does his/her bit followed by the sketch, the first part being pretty much what you're describing as '30s type vaudeville style comedy. Sometime near the end of World War II what for lack of a better term I'll call sitcom episodes (your "movie approach") began to become more frequent until they almost took over the show by the end of its run.
Oddly enough, though, Jack never abandoned the vaudeville/variety show format entirely, as we can see even in the last years of this TV series.