We may never know why, but many guitar players are afraid of music theory. The mere mention of it causes them to shutter in fear.
Please, do not be that guitarist.
I’ve heard (and read) many guitar players say that music theory will stifle your creativity (by the way, 99.999% of the time this is coming from people who have never studied music theory). They think, for some reason, that music theory will force you to do things a certain way, that it boxes you in with rules and regulations about what you can and cannot do with music.
This could not be further from the truth.
While music theory teaches principles, practices and informs you about what has been done in the past, it does not force you to do anything or follow any rules. You can learn all the “rules” of classical harmony, form, counterpoint…and then smash them to pieces. In fact, that is pretty much the history of western classical music in a nutshell. Composers learned that had been done in the past, and stretched the boundaries. Some of them literally smashed the rules into indecipherable pieces.
Music theory is actually extremely helpful! Theory helps you understand that “why” of everything you play on the guitar. It helps you understand the possibilities. It helps you understand why certain things sound good, and certain things sound awful. It can help you transform something boring into something wonderful.
It can actually unlock your creativity, contrary to what many guitarists believe.
Do not be afraid of music theory. Embrace it. Study it, and you will benefit greatly. It will help your song writing, improvisation, overall creativity, and performance.