This is one lesson from a full course with Gary Lee entitled: A Player's Guide to Guitar Mechanics. If you would like to take the full course you can do so by becoming a member of Classical Guitar Corner. https://www.classicalguitarcorner.com/join-cgc
Classical Guitar Corner is an online school for classical guitar and features some of the best educators in the world.
In this lesson you will learn how to measure your guitar's action, determine the best way to adjust and optimize the action, and gain a solid understanding of the underlying mechanics involved.
Gary Lee is a luthier based in Wayne, New Jersey (USA). His guitars are played by Ben Verdery and Fred Hand.