Fascinating article about musical hallucinations, a rare medical condition where a person hears music inside their head over and over again. Often times it\’s music they heard long ago.

The music-processing regions of the brain are continually looking for patterns in the signals arriving from the ears. As these regions recognize a tune, they amplify certain sounds that fit the music and minimize extraneous sounds.

Sounds like it\’s an extreme form of getting a song stuck in your head.
[ From Boing Boing ]