Not really a music but a sound FX on the C64 that really scared me to death back then.
You're alone in your room, it's late, you're not supposed to play videogames after midnight.
Suddenly, after the (endless) loading time of the game (on tape of course) a distorted monster voice SUPER LOUDLY screams the name of the game...
CHIMERA! CHIMERA!
Check it
here at 44'.