I was wondering if PPM's were around in the early days of Top 40 radio , 1950's / 60's / 70's ,if we would have be able to experience what many of us feel was "unique radio".
With plenty of jingles ,great DJ's and a plain "never ending fun sound" radio gave us.
I think we have to take radio broadcasting in context. By the early 1940s there were a lot of established stations, about half of which had network affiliations. The rest were barely scraping by with farm reports, live music shows to promote dances at local nightclubs, and "ethnic" broadcasters.
Between 1946 (the end of World War II, remember) and about 1950 there was a huge burst of new stations licensed. This just about killed radio because existing stations saw nearly double the competition, and TV had come on the horizon and the audiences for traditional network radio was fleeing the scene.
Stations, even network stations, were losing money left and right. The DJ concept, though it existed before, was now a must-have format because it became literally the cheapest way to keep radio stations afloat.
So, where we had KSFO, KFRC, KPO 680, KGO, KLX 910, KROW 960, KJBS 1100, KYA 1260, KWBR 1310, KRE 1400, and KSAN 1450 prior to World War II, most except for KRE and KSAN had very good signals (prior to solid steel office buildings and computer hash). So, all those stations could afford good programming and the other ones did ethnic or specialty programming.
Then the postwar period added KKIS 990, KSAY 1010, KOFY 1050, KNBA 1190, KIBE 1220, KEEN 1370, K-something 1430, KWUN 1480, KXRX 1500, KEAR/KOBY 1550, and KSJO/KLIV 1590, along with nearby stations such as KSRO 1350, KTIM 1510, KPLS 1150. KVRE 1460, KTOB 1490, and probably some more I can't remember.
Suddenly, a boatload of stations were struggling to get audience. So, the big stations got rid of their orchestras, their in-house soap operas, etc., and replaced them with announcers (DJs) and board ops. The small stations made do with DJs both announcing and board-opping.
But that wasn't enough, so the big stations hired comics and game show hosts and anybody else they could find who had had any kind of radio success in the past. And the smaller stations hired 22 year old kids who worked cheap and acted manic.
But that still wasn't enough, so the stations ran contests, and call-in song dedications, and jingles. Some stations went full force into news, which usually meant an important-sounding news sounder along with either a very serious-sounding news announcer or a cut-up news announcer, and teletype noises and basically AP wire copy. A few stations had someone who was friends with the local cops get tips from the cops about crime scenes (the days before police scanners, or for that matter before VHF and UHF two-way radio), who phoned them to let them know where to show up with their station "news car".
Slogans were big, and stations fought back and forth about that. KYA's "More music" competed with KFRC's "MUCH more music", and so it went. DJs were king for that brief period in time (well, the late 40s through the mid-70s) only because they worked cheaper than unionized network talent. By the mid-70s when the rest of the kinks were worked out of radio automation, it became even cheaper than the DJs.
Had the audience actually MINDED, the DJs wouldn't have gone away, but by the late 70s, people preferred the jukeboxes to the manic DJs and stations that boasted "30 minute music sweeps" got audience. So, automation was a no-brainer.
The best station to watch the evolution of commercial radio broadcasting is KLIV 1590. They went from a MOR full-service station to rock, to music sweeps, to all-news. They've managed to remain profitable because they caught all the major programming trends over the years.