Why is piano associated a lot with horror theme or depressive theme?

Learning piano professionally did affected my personality and way of thinking. But in a deeper way. I became a deep thinker with piano and writing. It didn't affected me in any dark ways instead it's a stress reliever. I guess because of that unique deepness in it's tone which isn't available in Guitar, Marimba, Flute or such.

Why is piano associated a lot with horror theme or depressive theme?
Post Opinion