Guitar Theory and Practice

Guitar Theory and Practice

Rock guitarists have a certain reputation among musicians. We might have great dexterity, but we’re the cavemen of musicians. We don’t know much about guitar theory – we can’t tell our subdominants from our phrygians, and surely you’ve heard the joke about how to make a lead guitarist play quieter?

“Put sheet music in front of him.”

And the simple truth is that you don’t necessarily have to know theory to learn guitar. Whereas a keyboard player needs to understand each different key, we just have to be able to find the tonic on the E or A string, because we learns scales by their shape.

There are lot of very successful guitarists who don’t know much theory at all. Jeff Beck, for example, is notorious for a relative lack of musical knowledge, and it hasn’t held his career back.

To be fair, however, lots of guitarists know a ton of theory. Jimmy Page and Joe Satriani, among others. I find it fascinating that Page knows a ton of theory, and Beck knows very little – and yet there is substantial overlap in their styles and influences – they even briefly played together in the Yardbirds!

But at the same time, there are real benefits to learning guitar theory, particularly if you want to move your solos beyond aimless “noodling” or you want to write some cool guitar songs.

Playing in G Major, you might know that your major chords are your 1-4-5, which is to say, G, C, and D. That feels kind of limiting, doesn’t it? But if you knew a little more theory you might know that the Mixolydian scale includes the 1, 4, and flat 7 major chords – that the F major chord if you’re in G Mixolydian.

If you just know your major scale, you might not even think to play that F major. After all, no F-chord exists in the G-major scale (in G Major, all Fs are sharp, so G-major contains the F# Diminished chord – don’t worry about that for now). And while moving from F major to D major can be interesting (to put it nicely) you can use G and C to transition between them, and viola – a tiny bit of theory has moved you beyond your basic 3-chord rock.

Guitar Theory

Of course, I suspect about half of you are scratching your heads and saying,


If that’s you, play G-C-D, and listen to how it sounds. Now play G-C-F.  Notice how the D and F feel very different against the G-C combination.

Another quarter of my readers saw the word “theory” in the title and skipped this post. And one thing I really believe about music is that you’ll improve the fastest if practice doesn’t feel like homework. After all, we all have plenty of homework as is. Music is supposed to be fun!

If you’re still learning scales by their shapes then maybe you haven’t mastered the whole fretboard yet and that’s just fine. There’s no need to rush to learn theory just yet if you don’t want to.

But when you start to feel limited by what you can do, don’t be shy about picking up a theory book. (I’ll be reviewing a few in a future post). You may be surprised at how it broadens your musical horizons … and makes trying learn guitar even more fun.

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