I love chord theory! Knowing your theory really separates good players from great players. The best players out there know their theory! Maybe it's the mathematical part of my brain but chord theory is hands down my favourite part of music theory. I love discussing it and sharing what I know with others. So I'm very excited to tackle making chord theory more accessible to the masses through my blog.


Prior to this post, I've posted a lot more about musical concepts or just motivation etc.. I also think this is very important so I'll definitely be revisiting this style, but for now I'm excited to make this more lesson-style and really sink in to some music/guitar theory that is extremely beneficial on so many levels.


I'm aiming to go slow, be clear and so this post will not delve too far beyond simple theory, however posts in the next few weeks will go further. But as this is the most foundational, it will also be the most meaty.


I'm writing this assuming no prior knowledge, so feel free to skip ahead where appropriate. Over a few weeks I will be going from very basic to quite advanced, hopefully all in logical steps. So there will be something for everyone.

Let's go:


Firstly, a chord is a cluster of different notes played at one time.


Today our goal is to understand how a major and minor triad works.



Ok before we go into that, I think it is important to have some grasp of the musical alphabet. So here below is every note in (Western) music.


A    A#/Bb     B    C    C#/Db    D    D#/Eb    E    F    F#/Gb    G    G#/Ab


As you can see there are 12 notes in total that repeat. A# and Bb are the EXACT SAME note, just different names used depending on which key you are playing with.


The interval between each of those notes (for example D - Eb) is what is called a "semitone". Moving the distance of two semitones is, of course, called a "tone", or "whole tone" or "full tone" (for example A - B). Some people prefer to use "half step" and "whole step" - exact same thing.


Do you understand?


Yes - continue

No - read it again

No for the 5th time - leave a comment, ask a question etc. but don’t give up.

So what's a triad? Settle down I'm getting to that now. Tri = 3, so a triad is a chord made up of three different notes, the most common of which are major and minor.


So when you see the chord "G major", it is referring to a major triad where the ROOT NOTE is "G".


Equally a "G minor" chord is referring to a minor triad where the ROOT NOTE is "G".


It is important to note at this point out that a major triad does not need to be specified, whereas a minor triad does, and often is with just a small "m" after the letter.




G = G major

Gm = G minor

A triad is made up of the root (or 1st), 3rd and the 5th.


Root - this is the name of the chord, the note from which the chord is built. So for example, if you are playing a "D" chord, the root note is "D".


The 3rd is what determines whether the chord is major or minor.

Very simple:

If the interval between the root and the 3rd is a major 3rd, it's major.

If the interval between the root and the 3rd is a minor 3rd, it's minor.


A major 3rd interval is 2 tones, or 4 semitones


A minor 3rd interval is a tone and a half, or 3 semitones.


So, looking back at our alphabet, C - E = major 3rd, while E - G = minor 3rd.


It is also important to draw out at this point that since you are going from the root (or 1st) to the 3rd, you are skipping one number, the 2nd, you therefore also need to skip one note name.


So for example, the major 3rd from "D" is not Gb, as that would skip 2 note names (E and F), it is F#.


Or a minor 3rd from C is not D# but Eb. Same note, just a different name and very important to be able to distinguish.

So that's the hard part. The 5th is a bit easier. The fifth of a major or minor chord is ALWAYS 3.5 tones away (unless clearly specified).


This is called a perfect 5th. It is not major nor minor as it is the same in both chords.


So for example the 5th from "G" is "D" (3.5 tones away and 4 note names).


So the 5th in G Major is "D".

The 5th in G Minor is also "D".



Another way of determining the 5th is by moving another 3rd from the original 3rd. From the minor 3rd you need to move another major 3rd, and vice versa for a major 3rd. This diagram below illustrates that a bit better.

Based on this information, it should be somewhat easy, but at least possible, to determine what notes make up any major or minor triad.


So a G major chord will contain G, B and D, while a G minor chord will contain G, Bb and D



At this point you may be thinking, "When I play a G chord on guitar I'm playing 6 notes". Actually, only 3 of them are different note names, you're actually playing G, B, D, G, (B or D), G. So while you may be playing 6 strings, it is only 3 different notes, just repeated an octave higher, or in a different register.



Let's look a slightly more tricky one


Db major


The root will be Db.

Two tones from Db is the major 3rd, F.

Another 1.5 tones away, or 3.5 tones from Db is the Ab.


Notice how we say Ab, rather than G#, as 5 is 4 numbers away from 1. So the name of the 5th needs to be 4 letters away from the root.


Try some yourself:






I hope this has been helpful. The next few weeks will be more in depth so it’s important to have this more foundational knowledge down.


If you have any questions, comments or want to get lessons, don’t forget to leave your comment below or contact me. Chord theory on!!!