There were vestiges of 1920s music in popular entertainment in part because Ed Sullivan gave air time to old vaudeville acts.
Then there were the variety shows (sometimes hosted by former vaudeville performers like Jack Benny or George Burns, in addition to song and dance numbers of shows like Laugh-In).
Also, there were a ton of familiar standards from the 1920s that got ‘revived’ in movie-musicals from the late-40s/1950s, in addition to tv-airplay. It kept alive a lot of old tunes, for later generations. Even cartoons utilized them.
A lot of younger people would hear these tunes and not even realize at the time that they were ‘not’ contemporary.