I just emailed the parents and they sent me some powerpoints full of statistics and a few links.
As I read through the links I see they often are quoting people in the music industry, so rather than get into a battle, I'll just say; do some research - you may be surprised at what statistics and studies really say.
No need to 'convert' anybody, but the evidence is there.
Having music as part of your curriculum does improve your grades and IQ in other areas, math included.

I do not work here, but the benefits are still awesome
Make your sound your own!