When I was in high school, my math teacher would play Mozart during tests, claiming it would help us. It would drive me crazy, and I doubt that my grades improved as a result of the distraction.
For what it's worth, I have a BMus in Piano Performance. I love music... but never as "background noise"!
But when I'm implementing the design, I find music very helpful. Just turning the code from design to actual code takes less focus from me, so I can end up getting distracted by other things in my environment if I don't have something else that can "fill up" the remaining amount of mental attention bandwidth. Also podcasts work even better than music for this.