Actually, I guess if you’re asking “why” when someone makes a scooter that plays MIDI songs, you’re barking up the wrong tree. It’s not about why. It’s about dee-deedeedee-doo-dee-doo.
What’s happening here is, apparently, there is a motor driven by the wheel, and by changing the pulse width modulation, the audible sound of the motor can be made to hit different notes. Have some converted MIDI information streamed wirelessly to the motor’s control board, and…