I know someone that was listening to a station when it changed formats in the early AM hours. He said they played a Godsmack song and went to commercial. The first song after the break was the Beach Boys with no announcement at all. That’s quite a change.
I’ve heard few enough of these songs that I probably would not tune the station out because I’d get to listen to new music, but of the four songs on this I’ve heard, two of them are bad (Californication and Yellow.) (Brian Wilson and Disarm are good.) (But I generally don’t like Foo Fighters or Goo Goo Dolls songs, so I probably would not like those either.)
Those two would be bad enough for me to not listen if that was all the station played (such as the aforementioned O-Rock in Orlando, as well as JRR 104.1.)
A radio station in Charlotte played construction noises for a whole weekend before switching…back to the same format. I still have no idea what that was all about.
There was a talk station in Portland, KGW 620, that changed formats in the middle of a show during a station break! All staff that were currently at the station were called into an “emergency meeting”, where they were met by security and escorted out of the building.
They didn’t even bother to call the other shifts and hosts to let them know not to come in.
They don’t always change the DJs… 990 Hits (previously 980 Hits) in Montreal changed overnight from a Top 40 pop-rock station to an all-oldies, all-the-time station. My adolescent self learned a harsh lesson about the adult world when I heard my favorite rebellious prankster “we’re not gonna take it!” DJ transform into a mellow buttoned-down milquetoast.
Don’t forget the polar opposite: “Alright fellowbabies. We are going to get down. This is Johnny…Dr. Johnny Fever…” 
I’ve been thinking about that the whole time I’ve been reading this thread.
So these sudden format changes can be blamed on young, hotshot, tight-panted executives?
Yes.
Well, the part about them owning most of the stations, anyway.
"And one more thing . . . BOOOOOGER!!"
I remember a radio station in Portland, OR, (Z100 I think) that for a week or so gave indications that it was shutting down. They said they were “pulling the plug.” The DJs were depressed and looking for other work. But when the time came, the pulling the plug reference was revealed to be nothing more than a weekend “unplugged” marathon giving way to a slight format change (something akin to going from Top 40 to Contemporary). The DJs were pissed at the deception* as was the listening audience.
*: They may have been in on it, but they seemed genuine.
99.3 WYSK in Fredericksburg, VA just switched from hard rock to…well I’m not sure what it switched to. 90’s R&B/dance music? Hell if I know. Harsh transition though.
If you go to their website they apparently still do rock on the Internet, interesting move but I really don’t want to listen to radio over the Internet.
As can most evil in the world.
BTW, as I recall, the general standard was to give DJs two weeks’ pay; more popular ones might have had guaranteed contracts. But in general, DJs lead a gypsy lifestyle, so they’re somewhat used to this.
What would be the point of giving notice?
“Hey you guys love your alt-pop, but we know you love Chritian Hymnals more and we have just the ticket for you this Friday…”
99.1 WHFS went from alternative rock to Spanish after the morning show. Quite jarring.
I can come up with worse. The legendary 99.1 WHFS in DC changed Mid-day from alternative rock to tropical latin music. The Sports Junkies were on when I went in to work that morning. When I got in to my car to drive home, I had a serious WTF moment, and had to look on the internet to find out what had happened.
On preview: curse you Madd Maxx for beating me to post!
Not always. Ratings and Arbitron returns have a bit to say, as well. Sometimes it is, indeed, about “giving people what they want.” 