At one .arket we had a PD who was in love with the writer of a certain tip sheet. Whatever the tip sheet guy put on his list, it was on our Playlist. Hence, we had a bunch of music nobody ever heard of and the vast majority were stiffs.
If you are talking about Gavin, Hamilton, FMQB and ones like it, the tip sheets did not have "lists" the tip sheet owner created. They reported the play of all the reported stations, generally giving a summary of how many adds, how many drops, how many up moves, and so on.
There is a difference between "most added" and "I think you should add this".
I asked the PD about this and his excuse was that's how we get record service by playing whatever the tip sheet said. It was awful.
That is not how record service was determined. It was based on format, market size and such. The smaller the market, the less likely you got free service. So you bought a new release service, such as TM's HitDisks.
The other stations had the hits and songs people knew and we had stiffs which went nowhere. Yes, I wanted to comment on the air about this but I didn't. Most pro's in the business would never run down there own sound.
What you are describing is a bad PD, not someone who followed the trades. Between the tip sheets and the magazines... Record World, Cash Box, Billboard and R&R and lots of format specific trades and publications, we knew what was working.
By the early 80's we had call-out and then, soon, after, full library music tests. In most larger markets, stations playing currents did both.. Any PD who did not follow listener tastes was, as I just said, a bad PD.