This is one of my projects to make musical instruments. I started with one servo motor and two glasses. The servo motor was attached to a pencil that moved between the glasses.

And then?

I took for servo motors, made laser-cut stands, got an Arduino, wrote a bunch of code in NodeJS and made music!

Awesome! How does it work?

Using metal wire, a pencil is attached to a servo motor. A servo motor can be controlled by transmitting an angle to it. The computer sends the angles via the Arduino (using Firmata). The NodeJS application on the computer has a midi reader, so that music can be read and translated to the right angles on the right servo motors.

Cool! Can I see it?

Alright then.