Yes, it was a very freeform broadcast, especially at night time. Ratings and getting a lot of songs on the air wasn't the priority. If you wanted that, but still liked a rock radio format, you would tune to 95.5 WPLJ. They not only played a lot of songs each hour, but were known to speed up the playback, so they could squeeze-in more commercials with the songs.
Mark Goodman moved from a Philly station to WPLJ in 1980, but soon left for some experimental startup, called MTV.