As an aside, the reason the most excellent show – WKRP – is played so infrequently in reruns or released in box sets etc. is because of the huge challenges/expenses of licensing the music.

Even though the songs are only used for a few seconds, it’s not like they like they could edit out Foghat (or Three Dog Night, or Average White Band) when Venus Flytrap or Johnny Fever introduces “… and now here’s Foghat…” Though the various TV re-runs and some boxsets so try to replace music with generic similar tracks (to great failure) 

Though some movies tried to change the soundtrack to skirt licensing fees when released on VHS (notably, Fast Times at Ridgemont High was sued by Danny Elfman for removing the Oingo Boingo song at the end… Mr. Elfman won, the song was reinstated and he cashed out, again).