I generally prefer to listen to ambient and instrumental tracks while I write, either that or lyrics I literally cannot understand. I find that if my mind begins to wander as I'm writing while listening to song lyrics, I'll sometimes start writing out what I'm listening to, rather than what I'm thinking about. 

Current favourites are a Japanese post-hardcore/shoegaze band called MASS OF THE FERMENTING DREGS, and Sea Power's OST for Disco Elysium.