Music is one of the main things I do for fun these days. I've played clarinet for more than 20 years, and now have an expanding collection of saxophones. The main groups I play with are the Fantasy Orchestra and the Ambling Band. They're great fun.
One of the most fun things I have been involved in was when I and some friends did a live tribute to Gong.
I also play bass guitar. My previous band, Dusty Cut, which I left during the PhD stuff, is still going strong in Cardiff.
Before that was the Random Lights, fondly remembered by probably fewer people than were in the band.
I used to compose electronic music (actually decades ago now). I'd love to again if I had the skill or attention span. Here's the one thing which sounds vaguely half-ok.