@lowrider57 Did you ever ask your interns what music they were listening to? Did you ever follow up on those artists?
There might have been more "diversity" on the Billboard charts (though certainly not ethnic or gender diversity), but only because mainstream music had to be a variety show of sorts back then. There wasn't the niche marketing, the targeted playlists, the Sirius/XM stations, the Tidal and Spotify playlists.
And yet many kids today have access to and listen to a wider variety of music than kids in the 70's and 80's.