Not even that, sometimes the same songs at the same time. Several years ago, I was cycling through the stations, and hit them playing the same fucking song at the same time.
That was Charlotte NC in the late 80's early 90's all the 'rock stations' all the time.
First off, they all have a boiled down list of probably 15 song max that are the essence of "classic rock" for those stations.. Those 15 songs will be 70%+ of what you hear every hour. In this day and age it's a super condense playlist (depending on who you have play rights with) and in all honesty I don't know how/why "live DJs" even exist anymore.