For the last... I'd say three books I've written music has made a big difference for me. In fact there are many writers who swear by music for inspiration and for background noise. In my experience it serves well for both. Stephanie Meyer is one for example who has written about being inspired by music and she's not the only one. On the other side many written works have inspired works of art whether they be music or paintings or whatever.
Music is a great idea to help get a writer out of a rut and into a groove. There are some bumps you can run into trying to mix music with writing. Here are some tips for trying it out. If you're going to write a high pressure, blood pumping moment in your project you should pick out a few songs that do that for you. Pick music that gets your blood pumping, music that paints the picture in your minds eye of what is happening in your project. The same goes for other moods, romantic moments, sad ones or happy.
Ideally you will select music that you know. This is because you want to have it in the background of your mind and not in the forefront which it will be if it's unfamiliar to you. You'll be trying to decide if you like the music instead of settling into a comfortable groove in which your fingers will fly across your keyboard. Try it out and see what works for you.
Right now I am trying out the website Pandora Radio in which you can input songs or artists and it will create a free radio station for you that plays like music. I am still deciding on it for my writing as it does introduce many new artists and that can be distracting but I love it for my everyday background.
Happy writing! I hope you find your groove :D