Why do some methods for learning an instrument seem to wo…

https://www.musical-u.com/learn/a-guitar-method-that-works-for-teachers-and-students-with-david-hart/
Why do some methods for learning an instrument seem to work better than others?

David from G4 GUITAR METHOD joins Musical U to share the secret of the 80/20 principle that works so well for his students.

https://www.musical-u.com/learn/a-guitar-method-that-works-for-teachers-and-students-with-david-hart/