Hi, I’ve been collaborating with a live guitarist, processing the guitar through my live coding software ‘Limut’, and live coding an accompaniment. Here’s a couple of examples:
Ambient: Limut Ambient Guitar Jam - YouTube
Industrial: Limut industrial Guitar Jam - YouTube
The setup is fairly simple; an Ibanez guitar with a Behringer USB preamp, into a MacBook pro running Limut (https://github.com/sdclibbery/limut) using the ‘external’ synth, which streams in external audio and allows the Limut distortion / filter / reverb etc effects to be applied. The webcam is also processed through the Limut ‘webcam’ synth, which streams in external video and allows video effects. One thing though; we found the input latency (lag) on the guitar was unplayable on Windows. However it’s fine on mac, seems like only a few milliseconds.
We’ve had great fun doing this, so I wanted to post here in case anyone wants to have a go 
Cheers,
Steve