In the following video Brad Meltzer says, "I write in complete silence. I never want to hear music, I don't want to hear anything while I'm writing, but there's no question that there's always a soundtrack that plays in your head while you write it."
It was the soundtrack in his head that inspired him to put together a companion soundtrack for his novel, The Book of Lies. He talks in the video about the process they went through in selecting the songs (ranging from REM to Wagner) and the time spent to find just the right music to get the reader "as close as I can give you to what I'm feeling as I'm writing it."
On his website, Meltzer has a score for the soundtrack, letting the reader know which part of which chapter each piece of music is supposed to fit. On the main soundtrack page you can find links to the complete playlist, as well as links to free downloads of some of the music.
Brad Meltzer - The Book of Lies: Companion Soundtrack
Music: REM, Richard Wagner
Book: The Book of Lies, Brad Meltzer