I always added my own "Secret Sauce" to music scheduling. I'd take a rule I did not use and rename it and make it my "station flavor" rule and give rules for it that had a "feel" quality ranging from "old and borderline sound" to "avant garde for my format" to "highly mainstream". I had rules about how many of each could go in a set and hour and which could segue into which others and which flavors had to rest a certain number of plays before another similar song could play.Here,, sometimes.. often really, i let the computer churn out what its gonna do, but were a special case.. but from time to time, ill see a pattern start to form on any given day, liek tempo or mood.. and try and then keep it moving by picking out songs that match the mood/tempo, and remove ones that dont.
That rule was not tempo, era, genre, gender based such as most station's rules are. They were qualities that the PD and I created and even had a "example list" to help us consistently catalog songs. This kind of feeling based rule meant implementing a new music test might take a week of trial, test logs and adjustments.
That was first used by me at a salsa station in the Caribbean, then a rock station and then a "Jack"-like format in LA and a dozen other Top 50 size markets. It always added something and each format was dominant. But it took a huge amount of work and a really good PD at each station.