Q: How important is music theory?
A: theory is made up. make up your own, but also check in to see how it compares to the theory that others have made up. music works the same regardless of what you call it. but if 2 musicians are working together and they want to talk about what they are doing, sometimes  it can be convenient if they have a way to describe what they are doing. that's the only place it comes in handy