In the past 20+ years I've taught music theory to students of all levels and ages, and believe it or not as odd as this might sound, many students begin seeing a reduction in their songwriting ability upon learning music theory.
What seems to be the case is that through the learning curve of amassing information on how music theory is both applied and used when analyzing music, the practicing student often suffers from what I'll simply refer to as: "information starvation."
In summary, this means many students, (at various stages of the music theory learning /development process), have just enough information to begin getting a grasp for music structure, form & layout, but not enough theory to fully understand music's big picture.
Therefore, this will often cause students to doubt what they're composing. Students will say to themselves, "I can't use that chord, it's not in this key." Over time this, "self-talk," can lead to composing troubles while songwriting.
In the grand scheme of things, a lot of this self-talk is due to a lack of being able to think both inside of a key's structure, as well as, easily allow for thinking outside of the key's melody & harmony and (of course) do all of this in an effortless way.
In the video lesson I explain several ways that students can shift their thinking to resolve these issues until they eventually complete all of their music theory studies.
Watch the Creative Guitar Studio Video Lesson to learn more:
Download a FREE handout and MP3 JamTrack at my Blogsite.