Jambole.com – for Guitarists

Have you ever wondered what a chord name like Cm7b5 means? How to read it, and how to name your own chords? If so then this article is for you!

First I’ll list the rules, there are some gotchas in there, and hopefully I’ll be able to point them out. I’ll then tabulate some example chord intervals.

Where do the numbers come from?

Let’s start by understanding where the numbers come from.

If I write out a Major Scale in “C”, I have…

C D E F G A B C D E F G A B C

No rather than having to worry about the note names, lets give each note a number.

C=1 D=2 E=3 F=4 G=5 A=6 B=7.

Then continuing onto the second octave, we have.

C=8 D=9 E=10 F=11 G=12 A=13 B=14 and finally C=15.

As you can see, I’m numbering the notes of the Major scale, not every semitone. So note 5 is a G. If I talk about flat 5, I’m talking about a G flat note.

Using numbers means I can refer to intervals in the scale, without having to worry about the key I’m in. So for example, note 5 in C major is a G. Note 5 in D Major is an A.

Triads.

The triad is made of 3 chord tones (hence the name triad), which define the basic chord harmony.

The Major triad

This is made from notes 1,3 and 5 of the Major Scale. In C Major, for example, these would be the notes C, E and a G. In A Major these are A, C# and E.

These building blocks are then arranged in any order, and can be repeated over any octave, to create a chord. So for example, you may find a chord containing the following intervals (low to high), E C E G C E. As you can see E is repeated 3 times, C is repeated twice, but this chord is still a C Major Chord.

The Minor triad

This is made from the notes 1 b3 and 5 of the Major Scale. The use of a flat 3rd rather than a natural 3rd is what differentiates a Minor Chord from the Major Chord.

The Diminished triad

This is made from the notes 1 b3 and b5 of the Major Scale.

The Augmented triad

This is made from the notes 1 3 and #5 of the Major Scale.

Easy huh!

7th Chords

Lets try making some 7th chords.

There is an additional type of chord added when we start talking about 7th chords. These are Dominant 7th chords. Dominant 7th Chords are probably the most common 7th chord forms, and for this reason, the word “Dominant” is often dropped so and the chords are referred to as just 7th chords.

In these types of chords, the 7th used is the flat 7th from the Major Scale. So if we were talking about a C7 chord it would contain a Bb not a B natural.

This differentiates the chord from a “Major” 7th, which would use the 7th note taken directly from a Major scale. In the case of C Maj 7 we would use a B natural.

Let me go through the triads, and see if it makes sense.

Dominant 7th or just “7th” chords. = 1, 3, 5, b7
Major 7th = 1, 3, 5, 7
Minor 7th = 1, b3, 5, b7
Min Major 7th = 1, b3, 5, 7
Aug 7th = 1, 3, #5, b7
Major 7th Augmented = 1, 3, #5, 7

So you see how the 7th is flattened or not by describing it as being a Major 7th or just a 7th.

Diminished Chords are managed differently. In this case a full Diminished 7th chord uses a doubly flattened 7th note (which is equal to a 6th). A Half Diminished chord (Sometimes referred to as a “Minor 7 b5″) uses a flattened 7th note.

Writing this out, we have.

Diminished 7th = 1,3,5,6
Minor 7b5 = 1,3,b5,b7 (Also known as the “Half Diminished” chord).

Extending this principal to Higher numbers

9ths are 7th chords (including the flat 7th note) + and additional 9th note.

Major 9ths are Major 7ths (with the unflattened 7th note) plus an additional 9th note.

11ths extend the stack of tones again, so they’re based on a 9th +plus an 11th tone.

13ths are 11ths plus an additional 13th note.

So If we had a “B b13 b9″ Chord. We’d use the notes.

B D# F# (from the B Major Triad)
Add an A (the flat 7th)
Add a C (the flat 9th note from the chord name).
Add an E (the implied 11th note)
Add a G (the flat 13th note, taken from the chord name).

In reality, when you get this many additional notes, its normal to drop some of the intermediate tones.

How about “Add” chords?

For example what about C(add13)?  In this case you’re asking for the C Major triad, with the addition of a single 13th note without all the implied 11th, 9th and 7th notes.

So this chord would contain a C E G and A notes.

How about Sus chords?

Sus Chords are also known as Suspended Chords. With these chords, you replace the 3rd with the Suspended number given in the chord name (either 2 or 4).

So a Csus2 contains the notes C D and G.
a Csus4 contains the notes C F and G.

Tabulating some examples…

And there you have it.

Deciding exactly which notes to use, understanding the fretboard layout. then finding the most comfortable shapes to use, can take a little time. So even with this theory, life still continues to be simpler if you use chord charts. However there is nothing to stop you working things out for yourself from now on.