I do not want to offend anyone and I say that because this subject is touchy and what I am about to say is a little pointy. I like to help people. You can do so only by communicating. This communication needs a language. The language in music is theory. I was asked to help someone with a jazz question. They gave me a progression using the number system you use here... I am at a disadvantage because it is not a standard that I am familiar with. The reason why I push theory is because it is like the saddle on a race horse. You do not need it persae, but it sure does make the ride a lot smoother and allows another rider to ride that horse too.
When I talk music with someone, I work with visual examples (notation) so they can take it home and practice as well as aural examples. If you train only one side of your skill set, you are only half as good as you could be. Here is a little story:
I went to college after touring around the US with my saxophone for about 10+ years. I never took a lesson but was naturally gifted. I practiced 4 to 6 hours a day and did played with some pretty good groups. I decided to settle down and go to college. I went to two auditions. The first was my entrance audition. This is where the put you in front of a bunch of old classical guys and they tell you to play old classical music... I never played a classical tune on my saxophone before in my life. In fact, I did not prepare a traditional song either, I took a song that I thought sounded classical, wrote a classical background track for it, recorded it in my studio and arrived at my first audition with a boom box, saxophone, and hair down to my butt. I thought the judges were going to pass out. I played my solo... It was a jazzed classical tune. They were a tough crowd. They had me sight read... YIKES. They had me play classical etudes. Double YIKES... When I left, I was fairly certain that I was not going to go to college here....
My second audition was for the jazz staff. I was invited to play with the top combo. I met the lead sax player in the book store earlier that morning and he told me that he would go easy on me that afternoon and try not to make me look bad... He quite that combo after that... right before I started school (still played in the lower band)...
They took me into the program because of my raw ability. They said it was scary. They fact that a scored an entire orchestral arrangement for my audition and then pulled that jazz audition is what did it. They knew I was never going to be a 'classical' guy.
I had no theory training up to that point. Four years later, I was eating people for breakfast. Why, I already had the natural talent. I needed something to tie it all together. I needed a way to express it to others. When I write a musical score, I need to know that others can read what I want them to do. When I teach here, I teach so that we are speaking with the same musical language.
I will use another example. If you do not teach a baby how to speak, he will develop his own language that is made up of grunts and none words. That is the nature of the human mind. We are a learning creature. God designed us this way. When I see so many people fighting against learning the basics of reading music and learning basic notational skills, yet taking the time to learn another form a non standard musical theory, I have to ask myself why? Why not learn something that is universal? That we can all share?
Theory has put a sharp edge on my musical blade. I picked up the keyboards in lightning fast speed because I understood theory. When I listen to music I understand the music that is happening but most importantly I understand WHAT and HOW it is happening. It saves time and I can convey that to others in a universal way.
Wolf