4 answers
Gina’s Answer
There is a field of neurobiology where you can study music and the brain - definitely requires math, science and music. http://en.wikipedia.org/wiki/Cognitive_neuroscience_of_music
You could also study acoustics or electrical engineering to design audio technologies - these are the folks who design speakers, headphones, etc. for great sound.
If you don't need your day to day to involve both music and math, you might also consider a career in music where you use your math skills to help the business - for example, finance but working in a performing arts or entertainment company.
Hope that helps and best of luck!
Michele’s Answer
Perhaps teaching? Can teach more than one topic/course. Also, music and math go hand in hand so chances are you would be good at composition.
Have you ever thought about composing music? Composers are needed not just for writing famous songs but even in fields like advertising (think commercials etc)
dave’s Answer
I am sure the math would help with time signatures, etc
good luck and listen to some Classic ROCK!