Only rarely do I write while not listening to music.  And rarely do I write while listening to music with lyrics.  This limits my music selection considerably.
Over the past 4-5 years, I've developed a long list of "favorite" ambient musicians.  Almost all of these ambient music "finds" come from Pandora stations that I've based on more mainstream artists or songs.  If you're at all inclined to listen to ambient music, whether it be while working, doing homework, cleaning,...