There's a charity for that! I am passionate about music, and so I was able to find some great ideas on the web by just doing a simple google search! There is: American Music Therapy Association: http://www.musictherapy.org/faqs.html; Mr. Holland's Opus Foundation: http://www.mhopus.org/; National Endowment for the Arts: http://www.nea.gov/support/index.html; and more! I also recently heard a radio commercial talking about a group that sends musicians to visit patients in hospitals to help brighten their day. What a great way to share your talents and serve others! There are lots of big ways to make a difference, but there are many more small ways.
Here is a challenge for you, google (or your favorite search engine) to find you some great charities that you can volunteer for, donate to, promote, or just plain be PASSIONATE about!