I have a Roland hex pickup and GR MIDI interface. It works … sort of. I’d never brave using one live. No way. But in a DAW environment, especially if you have abundant time to edit/correct all the glitches, it can provide serviceable results.
I’ve also used Melodyne to convert monophonic audio tracks to MIDI. That can be a lot of fun, and lead to some very interesting results. Time consuming though.