Several recent AM earworms

A few days ago on one of those nice mornings I woke up and my brain actually immediately said “woke up it was a Chelsea morning and the first thing that I heard”.
Joni Mitchell’s version of course. That’s pretty much an ultimate am earworm.
Then yesterday or the day before it was Donovan’s “Ferris Wheel” which is one of my favourite all time songs. Today it was the J. Geils Band doing “Detroit Break Down”.

All of which seems to give rise to a theory that my earworm generator really needs to have heard the song like a million times to put it in the hopper. It is very rare for it to pop out anything later than the eighties and if it does it is something we’ve listened to a whole lot. I could see it potentially using Rufus Wainright or the Eels or Dead Meadow or some evil jingle. But it seems to like the ones that I have worn a deep groove into either by design or by dint of early FM radio overexposure.