I can't write without music. Certain songs or artists just call up certain characters for me and it becomes that much easier to write them. While I was working on Curious for example, there was a lot of Alannah Myles floating around, and the MSV has a very extensive soundtrack at this point... strangly enough, it consists of music that Nan, Poly and Mad have mentioned that they enjoy, so therefore it reminds me of them!
I suppose that's just how my brain works. I hear a song, and it takes me to something or someone else and I just write from that perspective.... wow... that came out way too cheesy!