With the modern technology making such a huge impact on how we as humans function in our daily lives, learning an instrument has also benefited from this ‘advancement’. Now we can get training from any teacher or material from any part of the world meaning we can scout until we find the best resources to address our hunger for mastery.
I achieved this when I came across Mr. Arlen Roth. Considered the king of guitar teaching he certainly made a huge impact on my guitaring. I know there are other teachers which are also great (Marty Schwartz, Nate Savage, etc.) but for me Arlen just knows how to do it.