oldies76 said:
"400" is an estimated number that was a "ballpark figure" brought up in similiar discussions in previous posts dating back a few years. Stations with very tight playlists were always thought as having far less songs in rotation, while others had more. As a rule, CBS-FM has a smaller frequency of repeated songs (which in turn provides opportunity to play more cuts during regular times) than most other classic hits stations. Stations like CBS-FM with its wide selection of songs, can have up to 800-1000 or more "available" songs easily, but others with extremely tight and repetitive rotations will have far less.
In other words, you can't answer the question.
"400" is not a standard or norm for stations. Each format has a fairly consistent range, but there is nothing hard coded in this.
CBS-FM has around 800 songs in regular rotation. That can be seen by looking at individual weeks, excluding specialty shows (which seem, for some reason to be programmed in dayparts when there is virtually no listening to radio). That is within the range for similar formats.
A CHR that plays the power hits 90+ times a week is not "more repetitive" to the listeners. In fact, in perceptual questioning we usually find the highest perceptions of variety and the lowest perceptions of repetition among core listeners to CHR because the songs they want to hear are being heard often enough to satisfy their desires to hear their favorite hits.
Perceptions of repetition come most often because a station plays too many songs that appeal only to a sliver of the potential audience.
The goal of stations, including CBS-FM, is not to play more songs. It is simply to play all the songs that fit the format and which don't have big negatives on them. If there were only 500, that is what they would play. If there were 2,000, likewise.