The creator has 30 million combined views for this type of video, which is their only type of video. No other video on youtube seems to do anything similar. I'm most interested in how they generated the sine wave to be played. Does anyone know how they achieved it?
https://www.wolframalpha.com/input/?i=play+a+sin%282*pi*t*%2...
This plays a sound for 10 seconds. It start with a A (440Hz) and it goes to the next A (880Hz). The "frequency" changes linearly in my example, but you may prefer to change it exponential (like when you move the finger over a piano).
https://www.wolframalpha.com/input/?i=play+a+sin%282*pi*t*44...
This can be made with a lot of programs, I only choose Wolfram Alpha because it was easy to post an online demo.
I'm not entirely sure about the video component.