JRS Survival Guitar Lesson 18: Introduction to Chord Theory – Part 1

Welcome, intrepid musician, to the wonderful world of chord theory. Now that you’ve slaved through the previous seventeen lessons, it’s time to show you how these scales and modes relate to chords.

Why is this important, you ask? Simple. To make harmonious music, your melody line (played by guitar, voice, whatever) should share some common notes with the song’s underlying chords. A simple example: if your underlying chord is C Major, you know that your melody instrument can play a C note–and you’ll get good results. Your chords and melody are sharing a common note.

The chord theory I’m going to teach is a just an extrapolation of this simple principle.


First we must get all scientific-like, and make some assumptions:

  1. Chord theory is based on the current 12 tone scale (no micro-tones or other weirdness). Put simply, chord theory is concerned with all the notes on the piano keyboard–ebonyand ivory as they say.
  2. It is possible to create a chord theory system based on any arbitrary group of notes.
  3. Assumption number two is academically interesting, but in the real world, 99.9% of the musical population learn chord theory based on the Major Scale. This is what I’m going to teach.
  4. Basing chord theory on the Major scale does not result in losing access to any of the notes in the 12 tone scale. You still get to use all the black and white keys. Trust me on this.

cmajorscalepianoWell, that wasn’t too painful, was it? Let’s get down to some theory now. First, let’s lay out the notes in the C Major scale. I like the C Major scale because it is played using all the ivory keys on the piano, and doesn’t have any confusing sharps or flats. For the purposes of this lesson, we’ll stick to the key of C Major.

The notes in the key of C Major are: C, D, E, F, G, A, B, C (octave). If you need a refresher on the Major scale, go back and read Survival Guitar Lesson 1.

Moving on, let’s make a little note table, and have our first revelation about scales and their relationship to chords.


Our first revelation is this: Every key has eight notes (we learned that in earlier lessons). Likewise, every key has eight chords that correspond to the notes of the key. Look again at the note table. All I’ve done is write out the notes in the key of C Major, and give them roman numerals. Pretty fancy.

What you should get from looking at the table is that if you’re playing your melody in the key of C Major, you can rest assured that a C chord will fit with the melody, as will any other chord made from notes in the table. For that, my friend, is how chords are constructed. Chords are constructed using notes from a scale.

Now on to actually constructing those chords.


Interval: two notes. The name of the interval defines the distance between them.

Chord: three notes. The name of the chord defines what notes is consists of. And yes, I ended a sentence with a preposition. Sue me.

I keep those definitions pretty simple, eh? Why make it difficult? Anyway, here’s how to make chords to play along with your C Major scale melody. Let’s grab that note table again. We’ll need it to create our chords.


To create chords, we need three notes. Ready for another assumption? This is a big one. Western music has developed its collective ear to hear chords consisting of the root note, the third note, and the fifth note. This chord spelling (root, third, fifth) is used to create the basic Major and minor chords. Terms like second, third, fourth, etc. are used in music to describe two notes, and the space between them (their interval.

Let’s create our chords. It’s really easy. Notice that the chord spelling goes in odd numbers (1, 3, 5)? This corresponds to picking every other note from our note table (shown above).

Make some chords!

cmajorchordpianoTo create a C chord, we start with the root: C, then choose the third: E, and then the fifth: G. From the C Major scale table shown above, the notes in a C chord in the key of C Major are C, E, and G. We’ve just created a C Major chord.




dminorchordpianoTo create a D chord, we start with root (this time) D, then choose the third: F, and then the fifth: A. The notes in a D chord in the key of C Major are D, F, and A. We’ve just created a D minor chord. Don’t worry about the fact this is a D minor chord (even though we’re using the key of C Major).I’ll explain that in the next lesson.


Repeating this process for each note in the scale will create all the chords in the key of C. I’ve gone ahead and done your homework for you–check out the table below.

Chords in key of C Major

Root (also name of chord) Third Fifth
C Major E G
D minor F A
E minor G B
F Major A C
G Major B D
A Minor C E
B diminished D F
C Major (octave of root note) E G

Hopefully you can see that I’ve created a chord from each note in the C Major scale. I’ve created chords that are spelled (musically), root, third, fifth. There are a great many other chords we can (and will) create from the notes of our C Major scale. However, these basic root, third, fifth chords a great starting place. Why? Because these chords form the basic Major and minor chords in the key of C Major. Remember, the great revelation that you must take with you from this lesson is: chords and scales are related; they share common notes.

Now some of you technical people out there who already know some chord theory are going to holler at me that the actual chord spelling for a minor chord is: root, flatted-third, fifth. You’re right, and I’m not going to argue. I believe it’s more important at this point to emphasize that the basic Major and minor triads (three tone chords) are built using a root, third, and fifth, based on a Major scale. Also, by building the triads using each note from the Major scale (instead of the entire chromatic scale) the natural-third/flatted-third issue takes care of itself. So, please–no hate mail on this! I shall explain the intricacies of Major and minor chords in the next lesson.

So, my new chord theorists, read through this lesson a few times until it starts to sink in. Our job in Lesson 19 will be to learn about the difference between Major or minor chords, to explain further just what a flatted-third is, and to start using this knowledge to make actual music. Stay tuned!







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