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"!
Listen to music without human voices. Lyrics are distracting.
Maybe use OST music for films and games. This music is designed to not to compete for your attention with whatever you're watching or examining.