Using digital videos to learn new skills like playing guitar, is the most exciting advance since computers were invented.
The big problem is that most of the benefit is lost if you don’t have the ability to loop, slow down and repeat small sections of videos and maintain the pitch so that the sound is unchanged.
It’s no good slowing down a music tuition video for example if the voiceover sounds like Darth Vader on tranquilizers and the instrument sounds like a ‘wound down’ gramophone.
But no one ever designed a video viewing program that was specialist enough to do the very specific job of slowing, looping and repeating for the sole purpose of learning a new skill.