You are right. Wiki has a good music section for WKRP.Oh boy. I know the song in my head but can't think of the name. There is some confusion though because I believe in the syndication or re-release years later, due to copyright issues, they had to put in different music that was played. Am I right about this or just confused?
https://en.wikipedia.org/wiki/WKRP_in_Cincinnati
BD