Guitar/harp: connect picks to motors and fire solenoids which push metal balls up the strings. Percussion: Connect ‘magnetic’ thing . Push it forward and backward to generate some rhythm. Or just hit the drum, add some fancy LED around, flash with rhythm.
With these devices, you can trigger a MIDI instrument with audio input. It might be useful with those clip-on mics.
Ableton Certified Trainer Yehezkel Raz presents a set of two Max for Live devices. Peaks responds to incoming audio transients, and can be mapped to any parameter in Live. Notes, meanwhile, translates velocity data from its main knob into MIDI note messages. Use transients instead of peaks for more accuracy.