How to Be a Contributor to Musical Culture

Local colleges, including community colleges that teach recording arts and other schools and institutions that have choirs and other musical groups-- there’s something in it for you too, other than good karma. Help them record their work; if the compositions are covered by copyright, the mechanical licenses are not costly and can usually be gotten at a reduced rate for small, non-commercial distributions. Imagine listening to some of this stuff on your system if it is recorded simply. Pretty cool.
If you have professional chops as a business person, you can teach a seminar or do a guest speaker slot at a public forum-- part of educating the artist community. You don’t have to be a music business person to explain basics of good business practices. If you are a lawyer, volunteer some time to a pro bono organization for artists. Some cities have Volunteer Lawyers for the Arts type programs; others may offer similar services.
Find a local band you dig-- supporting them can take many forms- helping find them gigs at venues; introducing them to music they may be unaware of; introducing them to other artists (the biggest failing of young and not so young bands is the songwriting-- some of these folks can really play but lack material).
It isn’t just charity or being a good citizen-- there are tangible and intangible rewards for doing this, on so many levels. Good post there, @Erik!