Most guitarists pick up a few chords and scales as they learn their instrument, but it's not enough to just
know the stuff ... And it's not enough to know only the easy stuff ...
What matters to a pro-caliber player is knowing the truly IMPORTANT components of music theory — and knowing how that theory brings everything together ... in the songs you're learning, in the stuff you're writing yourself, in the way you jam and the way you work in a band.
When you're learning music theory, you should always be concentrating on how you're going to put it to USE in your actual playing.
It takes some time, but with the right approach and the right eye for patterns, it ultimately all CLICKS. And from that point on, you're talking a whole new ball game.
Pro guitarists THINK differently from amateurs. And while beginners tend to want to dismiss that idea, a large measure of the confidence they see in professional musicians comes from their complete mastery of music theory.
If you ever want to play in a serious band or get work in a studio as a session player, you've gotta learn this stuff.
So — To Put This In Practice:
* Tip 1: Start with the basics. You've gotta know your major and minor scales (all the patterns, every position). There are cool ways to master those in a shorter amount of time, but even if you don't know the tricks, just get in there and learn them.
* Tip 2: But don't just memorize patterns. Chord patterns and scale patterns are obviously the place you'll start. But soon as possible, switch over to thinking in terms of the NOTES you're playing and the INTERVALS involved in the various chords. This will not only help you learn stuff quicker, it will make you more proficient in every way.
* Tip 3: That one song you're learning every month? Break it down. Take the time to sit down with the sheet music or tab, and go through the whole thing. Figure out what key it's in. Figure out the chord progression (and why it works the way it works). Figure out the scales used in the various licks and in the solo. You'll be surprised at how much you can learn from even a single Iron Maiden song.