As mentioned, teaching is likely the most 'normal' and reliable job that I can think of that's still very hands-on and music oriented. Assuming you would actually enjoy doing it, studying music-ed and grabbing a job at a school of some sort teaching band isn't a bad choice. Strong union and whatnot. As for performing, there's a number of ways to go about it that might not be the most exciting proposition in the world, but can pay the bills. Solid, professional cover bands can make a killing in certain markets, and the live band karaoke thing does the same. I've known a few folks that spend summers doing stints on cruise ships in any number of dance/cover bands. Free room and board, food is covered, you get to see the world/country/wherever, and take home some cash every week. Hosting open mics can be a nice little way to make some cash on a weekly basis, etc.
Beyond performing, teaching, studio work, etc., some of the other obvious culprits would be the technical side of things: mixing, mastering, live sound, production, all that sorts of stuff. There are educational opportunities for all of these, but it seems that just diving in and gaining experience goes a very long way in these fields. There's always options like being a guitar/amp tech, or whatnot.
Then don't forget that all these companies related to the business (manufacturers, production companies, lighting companies, etc. etc.) all have room for all sorts of employees, if you're willing to get a little more away from the music directly. AR, promotion, marketing, sales, etc.
There's all sorts of ways to do it. It's more a matter of what aspects of music do you love, hate, tolerate, what sort of lifestyle do you want... that sort of thing.
