I'm curious, what are the odds of hearing the same artist four times in a row (meaning no commercial breaks, news/weather reports, or other songs in between, or anything else beyond a stinger), switching stations after each song? Or what are the odds of hearing the same song on four different stations at once? Well, I had both today. The letters in parentheses represent the callsign of the station.

Lady Gaga - Just Dance (KLUC)
Lady Gaga - Telephone (KLUC)
Lady Gaga - The Edge Of Glory (KQOL)
Lady Gaga - Poker Face (KMXB)
...all in a row with no gaps.

Taylor Swift - We Are Never Ever Getting Back Together (KLUC, KWNR, KMXB, KFRH)
...playing on four stations at once.

I remember once that "Wide Awake" by Taylor Swift was playing on one station (WPXY) and then another (can't remember for crap) afterwards. Two in a row is the closest I've gotten, but if anything it was the exact same song.

I don't know what station it was, since I was in my mom's old car at the time, but I heard Rihanna's "Birthday Cake" about 3 times on different stations. My mom doesn't like that song, and so she switched, and found it popping up everywhere.

My local stations are categorized mostly by era (Classic, 80's & 90's, Modern, etc.) So I don't have that problem very often. The only times I've heard repeating songs are during the holidays, where all you hear is Sinatra singing Christmas carols.