When looking through existing Arduino drum kit projects, [joekutz] noticed that most of them just used the microcontroller as an input for an existing MIDI device. That’s fine if you’re… ...

TheMIDInator MIDI controller has been created by Switch & Lever using an Arduino Mega with its 54 digital IO and 16 analog pins to provide a wealth of ...

YouTuber Alex Coover, aka Glacial Geyser, has build an awesome Arduino-powered MIDI controller to help with his budding music career. Here's a demo.

Jon Bumstead has created an awesome Arduino powered 13 note midi harp after receiving funding from the optics group Spectra at Washington University in Saint Louis.

Thorin Klosowski DIY musical instruments are their own thing entirely, but if you're looking for a place to start, Adafruit has a guide to building your own MIDI controller using an Arduino.