Back in 2013 I made a small guitar for playing Phase Shift by cannibalizing a Wii Guitar Hero controller. It runs on an Atmega 32u4 and is housed in laser cut plywood and acrylic, and contains some (poorly utilized) Addressable LEDs.
See below for pictures and the CAD file for the acrylic and Plywood cutouts files, as well as the source code that's currently running on it. This is a project I definitely want to revisit, by swapping out the 32u4 for a Teensy LC, adding many more addressable LEDs, and applying some of the knowledge of my IIDX deck lighting to this old project, as my skill with Addressable LED animation has grown substantially since I made this little guitar. I'll probably also replace the sad, unfinished, plywood with some nice hardwood, Look forward to an update or two in the future as I rework this one.