I vaguely remember late night AM radio, we didn’t get anything lower on the dial due to Cuban stations interfering (I’m in NC). The ones I recall were WLS Chicago, WOWO Fort Wayne, Indiana and there was a big one in New York but can’t recall the call letters. This is from my early childhood, by the time I entered my teens, FM had taken over for most music stations.
WWL,New Orleans, WBAP, Dallas, KVOO, Tulsa, talking of late night radio, all of these played all night country music, they billed themselves as Trucker’s radio. I loved WWL always having on every hour “a song of inspiration”. It was great.
http://www.virtualtruckroute.com/radio_personalities.html
There is still some of this. One show even went local but it’s ads, some talk radio and some music.