Growing up, the AM radio was the only way to hear music and know what to buy, if you were into that. In Sydney 2SM was the only station for that, and the above is a TOP40 chart from 1971.
I realize now, much of what became hits was only because of PAYOLA from record companies to have something continuously played. There were DJs that also played what they liked though...
FM Stereo didn't start in Sydney Australia till 1975, my second last year of Senior High School, the same year color TV was introduced. I had a part time job collecting shopping trolleys Friday afternoons and had joined a mail order record club.
In Australia, Countdown started in 1974, and the first time there was a country wide gatekeeper declaring what was hot to the 14 year old girls in their demographic. It did help Australian music. Must say Australian Pub Rock also got a little support. Even ROSE TATTOO got promotion.
I remember clearly listening to the massive hit MISEX track SPACE INVADERS, and the DJ getting sick of it and taking it off midway with a scratching sound. He had probably played it every 5th track in his shift and couldn't take it anymore in 1979.
About that time is when music videos became a massive music marketing thing too. It was still all the hits, with a few hits from Album Bands.
Music was important to me and the way you dressed and the length of your hair showed your allegiances.
The record companies pretty much controlled what you heard and knew about. Meant a band could be huge, as the population interested in music was force feed it.
In 2023 now, it has completely changed. There isn't that controlling force and the Internet has completely fragmented things. Still gatekeepers, but there are many of them, with smaller audiences.
It is also now so easy to hear any music anytime you want with Spotify or YouTube. It isn't all as special as it once was.
When I had to buy an expensive album, I played the album side completely through, and played the album many times. I studied it and the album artwork.
It was a different world then.