Really? 
 
I wondered if that happened to other people also, I *always* have a tune in the bacground of my mind: 
 
Sometimes I don´t realize as it is dubbed over by other sounds and noise coming from outside, but whenever I have time to relax and sit down without doing anything,.... whooosh! here it goes, the "current" tune (might be a song we all know or just a melody in my head, usually it´s around for 1-2 days until replaced by another).
 
If you ever meet me, just ask me the "current" tune, I can sing it to you (today it is a silly tune from Manu Chao - did a post on him in another thread - from the end of "Me gustas tu" that goes "Pala pim, pala pam, pala pím-púm-pám!" + the repeats and conversions in the song)
 
Anymore guys with an omnipresent tune in their head out there?
 
Always was wondering (I have been "hearing" those tunes for some 40+ years now) whether I need to see a shrink?
 
Really curious,
 
Rattler