Popular music has been on a fast-track evolutionary cycle since the invention of the radio and LP. Other factors have contributed, from the music press to cable television to more disposable household income in the United States after WWII. The idea that popular youth music would stay locked into the modes of mid-1950s America while culture and society shifted, millions of new teenage humans entered the scene every year, musicians absorbed new influences, and musical trends crossed borders and linguistic barriers -- and sometimes came back -- seems like a stretch.
But one thing that is not a stretch is what might be called Payola 2.0, after the 1.0 scandal described in the article died down. Record companies couldn't give outright cash payments to DJs, but there were many other ways of exerting influence on influential media gatekeepers. In my opinion, this is where the suits really were really able to promote biases and sideline non-mainstream musical trends.
Some of the influence was obvious. Picking artists that had the "right" look. Promoting "safe" artists. Selective access and backroom benefits for powerful DJs and music journalists and other influencers. Ignoring, sidelining, or co-opting trends bubbling up from the underground, from proto-metal in the late 60s to punk in the 70s to rap in the 80s.
And then there are the charts, which were segmented according to race and other factors aligned with the needs of the music "industry." Did you know that until the early 90s music charts in the United States were based on a sample of self-reported sales from record store managers? Can you imagine the bias and BS that went on with those numbers? As soon as soundscan was implemented, there was an immediate realignment, with rap and grunge and techno and country storming the pop charts. (https://www.nytimes.com/1991/06/22/arts/billboard-s-new-char...)
Since then, the digital transformations have resulted in an interesting fragmentation of pop music and youth tastes ... but with the music industry literally controlling major streaming platforms, we're shifting into Payola 3.0, and with whatever algorithmically dictated patterns that will entail.