http://www.borealisrecords.com/cd_endomusia.html

Cool--wonder how he learned the word?

Endomusia (the silent recall of a melody)

If you think "endomusia" is impressive, tsuwm, consider
"endosymphonia".

Beethoveen produced an entire symphony in his head while he was stone deaf.

That reduces "endomusia" to little more than an end note, wouldn't you say.

How come I can hear the music when I click on the link?

Bingley

How come I can hear the music when I click on the link?

'Cause some people just don't get it.

So what do you call it when a melody pops into your head and you can't get rid of it ?

Intrusive music, musical hallucinations.
http://www.dr-bob.org/babble/20020116/msgs/90809.html

We had a simple word for it in a thread not too long ago,
but I can't remember it. It must be very common, and usually
harmless, though unwelcome.

Ear worm

Dear Faldage: Ear,ear!

I'm immune, Dr Bill. I've been vaccinated.