I am sitting here listening to The Beatles and I want to say a couple of things regarding my comments on the question of whether or not to learn theory.
If you don’t know theory, and yet when a chord progression is played low on the neck you can play a melody in keeping with the chords halfway up the neck without being lost, you are doing well. In this case, there is no pressing need to learn theory because you can make music with another person, understanding as you do the numerical relationships of music. Though you may think of them as shapes, the relationship is a numerical one as numbers are a humans way of measuring distance. So theory shows a person how to be far away in terms of frequency (how high or low the notes are) but close in therms of feeling and connectivity.
In the article [Phil Ascott’s Interview with John Frusciante, TG150] I irresponsibly generalised that the reason people don’t learn theory is because they are lazy. There is another better reason not to learn it. If you have such a good flow of creativity going and are making music that fills you and those who hear it with joy, or if in your heart you believe you are well on your way to doing that, learning theory could slow you down as you brain would have to learn to function in a different way. I firmly believe it would help such a person eventually (as it helped Bach, Beethoven, Starvinsky, Frank Zappa, Charlie Parker, Miles Davis etc), but until a person can use this knowledge quickly and effortlessly without having to think about it, thinking theoretically will be a distration. Therefore, I encourage people to learn it when they have the time on their hands, like when they’re young or when they have no creative demands on them. Theory can deepen anybody’s expression (even the hypothetical people I mentioned who already understand basic ‘numerical relationships), but it doesn’t happen overnight. And in the meantime a creative person may think have lost something, but once they can access their knowledge effortlessly they will be more free and will have more colours to choose from.
I must also comment on one of Joe Satriani’s (much respect!) reasons to learn theory, from and otherwise fine lesson on this subject, where basically the student is asked “Can you play like Stevie Ray Vaughan?” thereby supposedly proving the need to learn theory. I postulate that none of the geniuses, who made great music without theory, knew they were geniuses when they were first learning. If someone feels they have the time, patience and brainpower to from their own conception of musical relationship and to figure it all out in their own way, then they should. I have learned as much from the styles of musicians who don’t know theory as I have from musicians who do. Many of them just found a unique style that resulted in beautiful music. Many of them don’t even understand the relationships I speak of too well and have to fumble around for 10 minutes before they play anything good, but when they do its something incredible. But by the same token let it be remembered that some people, like Hendrix, were just too poor to take lessons and would have if they had had the means. Hendrix was quoted as saying he would like to quit the music business for 6 months and go to music school. My own musical growth was compromised by not having enough money to pay the fee of the teacher I wanted to take from. But some of us have the desire to learn and the will to gain knowledge by whatever means necessary. Magazines like Total Guitar taught me immensely. In fact, I don’t know what I would have done without them. Life gives you what you put into it, and if you have the will to learn, practise and make music, it doesn’t matter if theory is part of the equation or not (but I recommend it).
Love is the law, love under will,