Lumberjacks and sailors are too far from town most of the time to be able to make the gig.

Farmers are too much like folksingers--they need another job just to keep farming. (I heard a farmer-folksinger refer to himself as a "two-time loser".)

I am a delivery guy (bread not pizza) and it is a pretty good counterpart to my musical activities, though not perfect since I work too late on Fridays to gig.

Consider the parameters. You need a day job, not one that puts you on night shifts or weekends, and you need to be able to arrange blocks of time off now and then, EXACTLY WHEN YOU NEED THEM.

Call centre agent and big-box store flunkie didn't really work for me.

A lot of musicians work in carpentry and other building trades. That's got a lot of advantages if you can hack it. (hah).
Usually straight days, rarely weekends unless you want them. Carpentry is one trade you can learn on the job like I did (although some training would help.)   Socially useful and sort of romantic.   
And once you become skilled, work is easy to come by--there's a chronic shortage of skilled tradespeople. If you are a free-lancer by nature, you can plan your own schedule. You could work part-time in the summer, then the busy season is the fall which isn't necessarily the busy season for music. I still do some carpentry but I'm trying to kick the habit--you get physically worn out after awhile (starts around the time you know what you're doing unfortunately).


W-O