I built a guitar consisting of multiple layers within two weeks. The layers consist of plywood and transparent acrylic (in alternating order). Each layer was laser-cut, though some components were 3D printed. I inserted some red LEDs in one of the middle acrylic layers to add a visual effect in dark environments. To make the neck more stable I used maple wood. Inside the guitar, I used 2 piezo elements connected to a self-designed PCB to pick up and amplify the sound of the guitar.
Note: I have no experience in building guitars, but I learned a lot about it through this project.