I’m not saying rock and roll immediately replaced all bb music. I stated that bb music was around in the sixties and into the seventies. I watched them on the Ed Sullivan Show and other venues. But my parents, who grew up during the BB era, never bought one album of any type of music. However, the future was dictated in the fifties when teens started getting their grubby hands on more money. Teens liked rock and roll and shunned bbm. When those teens got older, they didn’t start buying BBm albums, they started buying more r and r. If BBm would have been popular, it still would have made money.
The issue is why would people suddenly be willing to pay for a 4-piece band, when they used to be able to get a 30-piece band? There’s no denying that music would have evolved anyway, but it would not necessarily have evolved in the direction it went.
I bought the old rubber records in the 40s (still have some) then the vinyl LPs. After that I bought 8 track, then cassettes. Then the CDs came out and I bought them. Now I have Itunes. But I did like the big bands. My cousin’s husband is 85 and he still has a band that keeps busy in Kansas City.