It depends on how I feel to begin with, if I'm in a dark mood and put in some dark music orrrr a ballet I generally do something very deep and emotional, not always dark tho. Pop and upbeat songs for some reason make me want to do stars and water peices. Other times it's just background music to drown out everything else so I can get lost in my peice, or for me to dance to as I paint.
Absolutely. If I'm jamming hard to One OK Rock, I'm probably gonna be creating a scene where 1). Someone's getting their teeth knocked out by somebody 2). Someone's gotta veins popping out of their neck. On the other hand, if I'm relaxing to Miho Fukuhara, I'll probably be drawing a female character in a white dress with a tear drop on her face. That's all hypothetical but, you get my point. ^_^
Hmm... well, it depends, sometimes it actually does XD Like, if I listen to "My heart will go on" from Titanic, I may start making a love/pairing/couple pic XD But if I listen to something "evil" I may draw a really gory pic, so... it kinda does, lol XD
I usually choose the music after I thought of the theme of the painting... It has to fit. Haha... Sometimes I listen to music and want to draw something that fits to the mood of it... But it's usually the other way round.