[IggleSniggle]

If you don't mind using other limbs, there's a whole ton of products aimed at musicians who have their hands full but still want to be able to manipulate another device. For example, the organ, guitar pedals, and much, much more. Big variety of pedal setups generally, but musicians have been dealing with the "no hands" input problem for a very long time.

There are also a number of existing eye tracking input systems, but I think that kinda sucks / is limiting.

I'm aware of tongue-activated joysticks for people that are unable to move their bodies. Maybe look into assistive devices of that variety.

https://youtu.be/MtvpXr9O0J4?si=S8tJJm08_J5bzWMb

[ncarroll]

That is one amazing video and an utterly amazing musician. I had no idea such an instrument exists. Really, you kind of blew up my musical world. That definitely lands on my Things That Went Right Today list. Thanks!!