I am sure lots of writers have a "soundtrack" for their writing time: a collection of musical pieces you listen to when you sit down to work (or, y'know, get on your treadmill desk.) I don't remember ever seeing anyone specifically mention it in their acknowledgments page, though, until Stephenie Meyer's acknowledgments for the Twilight books, where she lists the band Muse as an important influence on her writing.
How about you? What's on your soundtrack? Do you create a specific playlist? Do you write to the same music all the time, or does each work get its own "album?"