I am the opossite.
When I don't listen to music I make stuff up in my head.
When I listen to music I'm just thinking: I would play it like that.
And like Matt Till said: it's good to listen to different genres.
To me it's metal, especially for complicated melodic stuff.
I listen to a lot of jazz, especially for my bass playing in the low register. And for my fretless.
Even simple punk rock can inspire me to great simple riffs.
Classical music... to me it's the same as metal

, only without screams and without electric distortion.