Patty Winter wrote:

of the songs that KYUU (KNBR's FM sister station in San Francisco)
was playing when I worked there in the summer of 1980. I counted
the carts once and figured there were about 400 songs in rotation.
Even in those few months, I heard each of them so many times that
they now jump out at me 30 years later as being "KYUU songs." :-)

And KYUU was a very popular station at the time. So, 400 songs is about 30
hours of music without repeats, though most playlists repeat some songs more
than others.

It goes back to that mythical waitress in the 1950s playing the same 5 songs
from the 200 selection jukebox that was the supposed inspiration for Storz top
40 format.