Hi,
It has taken me a while to post this here but I just wanted to share my project called harp of the city, which I built for Vivid festival in Sydney Australia in 2019. The installation featured 14 giant harps each with 6 strings each and 6 light bars. Each harp was entirely controlled by a Teensy 3.6. The teensy took the amplitude response for the strings, generated a PWM signal for the LED bars and also played back the samples to speakers connected via the audio board. The harps were fully polyphonic. And in my opinion we’re very beautiful. I have a attached a video of the work here.

Vimeo: https://vimeo.com/349590328?ref=em-share

I would be very happy to share the code and the hardware designs for the control board I designed to connect up the guitar pickups and led drivers used in the whole design.
Long live Teensy Open source!
Josh.