I did a six week report and got 610 songs. There are a lot of them that rotate in and out, with either rest periods or very slow rotation.
Correct. Looking at Mediabase, there are about 200 songs that were pulled out at the of last week, and replaced by a different batch of songs. The oldest song played last week was "Summer In The City," which was likely done because of the record heat, not to bring back 60s music. That was a one-time spin, and was not returned to the playlist this week. This week's oldest song is American Pie from 1970.

