Consider creating yourself a playlist (or two, or as many as you need) to put you into the right mindset for writing. Not just of music but of nature sounds as well. Rhythmic beats. Bird calls. Maybe one character is an angry, aggressive teenager. Create a heavy metal playlist to listen to when writing him. Maybe one character is the quirky, adventurer type, and you think polka fits her personality. Create a polka-for-adventures, music-for-fiction-writing playlist, and get into her groove when you’re writing her dialogue. Maybe another character is a new mom, and you want to give her lullabies to sing to her baby late at night. Listen to what she would listen to, and feel what she feels in order to write her so the reader can hear her.
Explore, listen, save. Get out of your normal radio stations and discover deep cuts, live versions, and underground artists in genres you’ve never heard. Consider international music and let the sounds of other cultures impact your mental rhythms. Consider swing, classical, electronic, reggae, Mongolian throat singing.
Save some music that catches your attention and your creativity, and return to them for inspiration, for a change of pace, or to loosen up your thinking when writing fiction or nonfiction. You may be surprised how indulging yourself in sound can make your fingers dance across the page.