I'm a musician and developer/architecture consultant. My goal since day one of tech work 15 years ago was "fund music life better", so I hear what you are saying. I currently average half-time and make a comfortable middle class salary.
The big thing to realize is that there is a huge difference between "I want a job where I can do minimal work and mostly do my own thing while still getting paid" and "I want a job where I can earn my living in 2-3 hours a day". I have done both, the first when young in non-tech fields, the second for the last 15 years in tech. I work very hard on those 3 hours a day, in a role where deadlines can never be missed and we are part of $100M+ transactions. I take that work very, very seriously. But I get paid enough to do my 18-20h a week and spend the rest of my time pursuing the arts, with no pressure to have to figure out how to monetize my music (a very nice thing).
If you're after the second, (hard, short work, for high money), you want to find specialized expert work where you are (as you astutely pointed out) out of the production loop. Consulting is the best thing I've found. When I'm on a gig with a client, they get me 100%, totally focused. When I'm off the gig, no one expects me to get back to them sooner than a day, allowing me to do grad school in music. The key to finding this work is to become an expert in some subfield of tech, and get really good at the human side. Writing, pubic speaking, negotiation, client relationship management, project and timeline management, etc. Not many techies want to get really good at those "soft skills", but if you do, and you are an expert in something, consulting firms will value you highly.
Another good option is contract tools development or freelance contracting for folks who need code only occasionally. Lots of companies will hire part time contractors to improve internal systems, and you're still out of the product deadline loop. I've done that too and still do it sometimes for scientists. Python and SQL are good for that area.
The big thing to realize is that there is a huge difference between "I want a job where I can do minimal work and mostly do my own thing while still getting paid" and "I want a job where I can earn my living in 2-3 hours a day". I have done both, the first when young in non-tech fields, the second for the last 15 years in tech. I work very hard on those 3 hours a day, in a role where deadlines can never be missed and we are part of $100M+ transactions. I take that work very, very seriously. But I get paid enough to do my 18-20h a week and spend the rest of my time pursuing the arts, with no pressure to have to figure out how to monetize my music (a very nice thing).
If you're after the second, (hard, short work, for high money), you want to find specialized expert work where you are (as you astutely pointed out) out of the production loop. Consulting is the best thing I've found. When I'm on a gig with a client, they get me 100%, totally focused. When I'm off the gig, no one expects me to get back to them sooner than a day, allowing me to do grad school in music. The key to finding this work is to become an expert in some subfield of tech, and get really good at the human side. Writing, pubic speaking, negotiation, client relationship management, project and timeline management, etc. Not many techies want to get really good at those "soft skills", but if you do, and you are an expert in something, consulting firms will value you highly.
Another good option is contract tools development or freelance contracting for folks who need code only occasionally. Lots of companies will hire part time contractors to improve internal systems, and you're still out of the product deadline loop. I've done that too and still do it sometimes for scientists. Python and SQL are good for that area.
HTH