Mario, the only thing I question is where you said "If you can play a lead in C you can play it in any other key."

Really? When that open G string in the middle of the scale is no longer open, what do they do?

See, knowing the neck well enough to touch every F on the neck without counting or thinking IS reading and knowing theory. You are reading the neck and knowing the interval between the nut and the fret. Then have them do that for Bb. Then Db. You don't have to know that F is the top line or the bottom space on a sheet of staff paper, but you have to know where it is on the neck.

What has to be established here is the end result that a new player desires to achieve. You and I started very young. We were not in our 50s looking to entertain at the cookout. And people who took up music later in life certainly didn't do so with the same career aspirations as I did as a 5 year old kid who heard big band music like The Dorsey's and Glenn Miller literally since birth. That focus went away when I was 11 and heard The Beatles for the first time. and those chord changes on She Loves You where the intro moves from an A7 to a C, and right there I was hooked. That chorus from root to 6 minor to 4 minor... genius. Now, as a kid who learned theory, I was able to learn that song without an instrument in my hands. I sat there and said out loud "G....... Em......... Cm......... D" So, 1-6-4-5 but the 4 was minor, unique to me. But not everybody can learn that way, and more importantly not everybody WANTS to learn that way. I know most of us can do that now, but geeze, I was like 12 or 13 when they finally came on a tour. Plus, seeing them live was a waste of time because nobody heard the music anyway.

Different methods, one of which fits the end game of the one learning. What I find sad is that those who never learned theory immediately attack those who did and found it valuable. Ear training is fine. I am aware of the list of people who can't read. What is odd is to hear people say "I don't know jack about theory" and then the next 15 sentences talk about "And from there if you go to a diminished, and then to a minor 4th..." That IS THEORY!!!

I speak of Tom Bukovac often, and if you visit his youtube he constantly reminds us that he can't read and never learned theory. Well, he may not have sat in a classroom for a class called Theory 101, but he knows theory better than most. You don't get to be Nashville's studio golden boy by accident. He is good beyond description. And self taught. Musically. Experience-wise, he had MANY teachers along his journey. The point is that when you know theory, formally or informally, the difference is like jacking a car up with an old school ratchet jack or a more modern floor jack. You'll get the car in the air either way. Players who can sit down with their guitar and immediately recognize and anticipate changes from pattern memory DO know theory. My god so many of you hear that word and go into "mother bear" mode. It's just tools. In my case I didn't have a choice. My first teacher demanded 6 weeks of theory before I could touch a piano, much of it an a plastic keyboard mock-up and he pointed to a note on the blackboard and I had to show it to him on the keyboard. Then he'd say "And what is the 4th note of that scale?" or "Show me the whole steps and half steps of that scale". I wasn't even 5 yet! He didn't hit me with Ionian and mode and Aeolian mode the first day. In fact I didn't get that until college.

It's just tools.