I must say, almost ninety percent of my writing is sparked by music.
Something about the way I can connect my characters to the lyrics of the music, and the way the melody and beat moves me makes a scene just play itself out in my head. I rarely write in silence, but I can't write if the songs keep changing, so I put it on repeat to keep the atmosphere constant. If I don't have a really good song stuck in my head, my writing tends to be bad. Actually, I tend to not write at all : D.
Also, I seem to be able to write really well when I'm sad or angry, so I'm guessing the reason why music inspires me so much is because it can more easily emotionally move me.