The music comes from the four stepper motors. These are usually found in robotics projects, as the degree, speed, and direction of rotation can all be controlled in software. The rotation creates noise; when controlled, the noise becomes a note, which the user can change using the capacitive touch keyboard. It’s quite simple, and all the more brilliant for that.
Just because you’re experimenting with stepper motors, perfboard, and a whole nest of wires, doesn’t mean you shouldn’t try your best to make your creations beautiful. Take this thoroughly modern musical instrument by Instructables user thisisnomine: in the back it’s your typical maker project, with PCBs, breakout boards, and wiring. From the front, though, it’s a feast of mid-century hardwood, with mother of pearl detailing and a combination of two African hardwoods (Anigre, the light coloured wood, is used here as a veneer, with the rest of the housing made from sapele, which is similar to mahogany).