You can add another person to that list, me!

I'm currently working as a software engineer, but I made my living as a musician (jazz, blues, piano bar) for several years.

I could see jazz especially being interesting to tech folks. There's a fantastic mixture of theory and logic and puzzle-solving mixed with creativity and expression that meshes very well with hacker culture, at least to me. I personally know quite a few people who are into both.

It's also something that can be largely self-taught, which mean a lot of the people who are into it are into it because they're passionate about it.