Check out the KMel Robotics Flying Robots that can Play Instruments. The control of the quadcopters is amazing to be able to play these notes with the accuracy and timing that they can!
“Just a reminder about how this all works: each one of these robots has its position measured down to the millimeter (or better) at a very high frequency using an external localization system. The individual hexrotors themselves are being centrally controlled by a computer somewhere else, sort of like a puppeteer system.”
Via: IEEE Spectrum