Is it a million dollars and ten million fans? That's one yardstick, but it isn't everyone's.
There's a musician whose work I like, kind of a folk singer and kind of not, a young woman who plays at least nine of every ten instruments in her recordings. A decade ago, she was working one of the low-paying, steady, skill-related jobs many musicians do, music director for a church or some such thing. One morning she looked around and thought, No. My head's full of music and if I don't start playing more of it, writing it down, recording it, I'm just going to explode!
So she quit. Started playing small venues.
...A half-dozen CDs later, a dozen rambling national tours appearing in slightly bigger places, to more and more people, living in a medium-sized apartment with a growing pile of instruments and computers, she reports:
"I'm taking home about what a Taco Bell worker makes -- but it feels like a lot more."
Sure, her gross is higher and so's her overhead; put that spreadsheet away. Part of her "income" is getting music from inside her head to inside yours. And to people who like it enough to pay for it.
I'm not sure you can put a cash value on that. I suspect a wage/hour expert would crunch the numbers and walk away, sadly shaking his or her head. On paper, the ROI isn't much.
But -- if you're doing what you want to do, not missing any meals, keeping the bills paid -- aren't you richer than the guy with the nice car, the big house and a high-paying high-pressure job he loathes? No matter how much he earns, he can't afford what you've got.
5 months ago