It’s time to learn about the awesome power of the third. And look, you don’t need to know this stuff to play guitar, it’s just cool. Wow, I actually heard you say “uh oh” from here. Your sense of foreboding is correct: this article contains music theory. It won’t hurt too much, I promise.
the triad
A basic chord in music is made up of three notes and is called a triad. Let’s have a look at the E major scale as an example. (For a slightly deeper dive on scales have a look at Unraveled: The Blueprint of the Major Musical Scale). The notes of the E major scale are:
The notes that make up the E major chord are E, G#, and B, and you will perhaps notice that these are the first, third, and fifth notes of the scale.
Since a guitar has six strings and not just three, it’s common to see the notes of the triad repeated in the same chord. When you strum that standard E chord in standard tuning, here are the notes that you’re playing:
So you see, the notes of the triad are well represented here.
Let’s look at another example, this time with the C major scale and the C major chord. Here’s the scale:
This time, the first, third, and fifth notes are C, E, and G. So when you strum a standard C chord in first position, here are the notes you’re playing.
Yep, there are the notes of the C triad.
I think it’s worth noting here that the low open E string doesn’t always fit that well with the full C chord in first position. As guitarists we usually want to emphasize the root of the chord and that would mean starting our strums at the fifth string with the C note. Still, from a theory perspective, the E note is a member of the C major triad, so it’s acknowledged here.
the power of the third
If I had to choose the most powerful note in any chord, it would undoubtedly be the third. Why? It is the note that establishes whether a chord is major or minor. Let’s look at the E major chord again. The triad for E major is:
If I were to lower the third by a mere half step from G# to G, I now have the awesome E minor chord and the triad becomes:
If you’re playing along with this article (if you are, then yay!), strum the E major chord, then just lift your index finger and strum again for the E minor.
It’s of course the same for the C major triad and chord: lower the powerful third by a half step from E to E flat (Eb), and voila, C minor!
When it’s time to strum this on the guitar, the first position C minor chord presents a problem in that half the strings have notes that no longer fit in the C minor chord. The solution is just to play the three notes of the triad and call it good!
why this is cool
Well, because I’m a nerd about such things, I think this information is cool all on its own. I mean, come ON. One note can make that much difference? THAT IS SO COOL.
Also, this information is of course applicable across all instruments: it’s instrument agnostic. (Is that a thing?)
Finally, there are songs out in the world where the progression moves directly from a major chord to its minor sibling. The chorus of David Bowie’s awesome “Space Oddity” leaps to mind:
Also, the distinctive intro to Eric Clapton’s “Lonely Stranger” follows a similar pattern:
So there you have it, you now are enlightened as to the power of the third in music theory and how to see it work on guitar! Have any comments? Drop me a line at imperfectguitarist@outlook.com!
