We had some limited music classes in school -- 1 hour every two weeks or so. No instruments other that tamborines and indestructable percussion instruments and triangles and such. Typically, it was horribly dull. On the other hand, we occassionally learned songs in other classes, particularly historical and patriotic songs. It seemed completely natural and unforced, which is probably why I can't remember a single song I played triangle to, but I remember lots of Woodie Guthrie tunes from history and politcal classes :)

Things to do:

-When asked "why music," point out that numerous studies show that kids who study music have better spatial reasoning and significantly better math skills -- and that shows up on those standardized tests. Even in adults, those who study music have an auditory complex (the part of the brain that comprehends and translates all kinds of sounds) as much as 25% larger than those who don't.

-A guitar is cheaper and lasts a lot longer than a computer.

-Donate time repairing and maintaining instruments to struggling programs as a way to help them meet their budgets.

-Schools that can't afford music teacher's salaries might be able to let you hold events in school space after school.

-Especially in inner city schools, the need for quality yet fun after school programs in community centers is critical. Look for ways to volunteer -- and open a participatory music forum that will make the kids interested. Trying to teach Carter Family songs to kids who have grown up on hip hop won't fly... but you might get them interested in the process while giving them what they want to hear and play.

-Support or sponsor local music contests, especially those aimed at high school students -- most of whom now rarely have mandatory music classes of any kind, but they are old enough to decide to make the effort on their own. Everyone loves prizes and winning contests!