Debussy said, “Works of art make rules but rules do not make works of art.” In the case of Debussy, he was trained in theory and rejected many of the rules. He used theory to write chords and understand scales. However, he rejected the traditional ideas about voice leading and resolving dissonances. He embraced atonality when he used the whole tone scale. I put him in the knowing the rules first and then breaking them camp.
Completely untrained musicians can be found in rock music. The visionaries Captain Beefheart (Don Van Vliet) and Brian Eno created unique genres knowing little or no theory.
In the case of Captain Beefheart, he needed a musician trained in theory to communicate the Captain’s vision into something the musicians could play. In the original Magic Band, Alex St. Clair fulfilled this role. Later John French took over the role.
Contrast Beefheart with his buddy Frank Zappa. Zappa knew quite a bit of theory and could read music. He could communicate what he wanted directly to his musicians. He was also a visionary.
On the other hand, if you like the raw emotion of the blues, again theory is not necessary. The blues is about listening, copying from the greats to get basic phrasing and feel and then let go of the licks you copped and find your own voice. Both Zappa and Beefheart were strongly influenced by the blues.
I think that both approaches have merit. Some people fear that theory would limit or constrain their imagination. I disagree. I think knowing theory will keep you from reinventing the wheel. For example, when I write I know how to create my own scales by knowing how treat each step of the scale differently to get a particular sound. Without theory, the process would be hit or miss.
Of course, it also allows you to communicate directly with your musicians without the need for an intermediary.
If you read music, then I recommend. It is written from the perspective of classical music. It covers a lot of material including musical form, which is unusual for a theory book.
If you rather have a jazz theory book, I found this on Amazon. It got a 4 1/2 star rating.
If you are looking for more of a Rock or Pop approach, I found this on Amazon. It also got a 4 1/2 star rating.
©2017 Stephen L. Martin
Photograph: Claude Debussy (photo in public domain)