Your first link doesn't work work for me,
Fixed
but this isn't directly considered "stop-motion".
I was thinking that i got something wrong somewhere...
taking pictures of your hand on certain keys and playing a note over it
nope
if you look closly it is not pictures, i started recording, pressed the note, stopped recording, moved the camera, started recording, pressed the note, stopped recording, moved the camera, started recording, etc.
And then i got the video files and cut them and put them in.
it's not stop motion since you're using a video for each frame.
what is it then?