Music -- fitting music, especially -- is an integral part of writing. More often not its a song that influences the way I write and and can even kick away my writer's block. Plus, writing without music is like watching a movie without a soundtrack. You understand whats going on, but theres not much tone or mood to get you sucked in.

There's also something about music that can influence new ideas and thoughts. How some somber lyrics can inspire a quiet, moody character, or an epic orchestra can spark the start of a story surrounding daring knights on a quest for some unknown land. 

Though finding THE perfect songs to set the mood can be difficult. At least, it is for me [s]because I'm a finicky little bastard[/s]. Though a quick search on Google can usually solve that problem.