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Chords in music: A Complete Guide

Chords and chord building are a vital part of music theory and are the foundation of all music. In fact, it is impossible to write a piece of music without them! In this post we will explore what chords are in music and music theory, how to write them and build them, how to invert chords and how to label the chords and also how to use them when writing music.

What Exactly is a Chord?

A chord is simply a set of notes or pitches that are played simultaneously. Chords are most commonly built using superimposed thirds. A chord is essentially two or more different intervals, the interval of a third most commonly. If you do not feel confident with intervals do make sure to read the blog post on intervals before embarking on this post about chords. 
 

The chord type that we most commonly see and use is the triad. Triads are simply three note chords. 'Tri' comes from the greek language and simply means three, think about a triangle!

A chord doesn't just have to consist of three notes, it can also consist of four or more notes. The most common types of chord that have more than three notes are seventh chords or extended chords, but more on this later. Let's look at triads first.

What are triads?

As stated earlier, a triad is a chord consisting of three notes. It is built using the root, a third above the root and then a fifth above the root. See below an example of the C major triad. The notes in this triad are C, E, G.
triad, c major triad
A triad is a type of tertian chord. A tertian chord is where we stack multiple thirds on top of each other.
 

In order to confidently build chords, you need to be really certain of your scales. Knowing and understanding your scales helps you to know what notes to include in your chords. To refresh your memory on this topic make sure to check out the scales blog here!

It is also useful to really understand what intervals are and how to work them out as chords are built up using different intervals. Having a clear idea of not only how to work out the intervals number but also its descriptive word is vital when learning about chords. When reading on you will see why.

Let's write out the scale in the key of C major. There are seven notes/degrees in total in the C major scale and we can easily write a triad on every single one of these scale degrees. By the time we have finished there will be seven different chords.

C major scale triads, Roman numerals labelled
As you can see, each chord includes the root, a third above the root and a fifth above the root! Remember, the root is simply the bottom note of each triad/chord.

 

Make sure you notice that each of these chords is either written on all lines or all spaces.

Chord I includes the notes c, e, g

Chord II includes the notes d, f, a

Chord III includes the notes e, g, b

Chord IV includes the notes f, a, c

Chord V includes the notes g, b, d

Chord VI includes the notes a, c, e

Chord VII includes the notes b, d, f

There are four main triads that you will come across and these are:

  • Major Triad - A Major third and a Perfect fifth above the root
  • Minor Triad - A Minor third and a Perfect fifth above the root
  • Diminished Triad - A Minor third and a Diminished fifth above the root
  • Augmented Triad - A Major third and an Augmented fifth above the root
Let's explore these in more detail.

Major Triads

A major triad is built using a major third and a perfect fifth above the root.

Let's look at the major chords in the key of C major.

  • Chord I - This includes the notes C, E and G
  • Chord IV - This includes the notes F, A and C
  • Chord V - This includes the notes G, B and D
C major triads, chord I, IV, V
In a major scale, chords I, IV and V will always be major triads. Whether this be in the C major scale, F major scale or any major scale for that matter!

Minor Triads

Minor triads are built using a minor third and a perfect fifth above the root.

Let's look at the minor chords in the key of C major.

  • Chord ii - This includes the notes D, F and A
  • Chord iii - This includes the notes E, G and B
  • Chord vi - This includes the notes A, C and E
Minor chords, chords ii, iii, vi
In a major scale, chord ii, iii and vi are always minor chords/triads. Whether this be C minor, A minor or any minor scale for that matter!

Diminished Triads

Diminished chords/triads are made up of a minor third and a diminished fifth above the root.
 

Let's look at the diminished chord in the key of C major

  • Chord viio - This includes the notes B, D, F
diminished triad, chord vii, C diminished
In a major scale and a minor scale, chord vii is always a diminished chord.

Augmented Triads

Augmented chords/triads are made up of a major third and an augmented fifth above the root. In a minor scale chord III+ is always an augmented chord. There are no augmented chords in a major scale.
 

Let's have a look at the augmented chord in the key of C majors relative minor - A minor.

A minor augmented triad, Chord III, augmented

Chord III+ in A minor includes the notes C, E and G#. Notice how we have a G# in this chord, this is because G# is A minor's raised seventh note.

We most commonly use the harmonic minor scale when writing chords.

By raising this note we end up with an augmented 5th between the notes C and G#. 

Common Seventh Chords

Seventh chords are triads with an additional note, this additional note is a seventh above the root.

There are six common types of chords in this section:

  • Dominant seventh chord
  • Minor seventh chord
  • Major seventh chord
  • Diminished seventh chord
  • Half diminished chord
  • Augmented seventh chord

There are more of these types of chords in your music but this is a great place to start.

Dominant seventh chord

Dominant seventh chords are built using a major triad on the fifth note of the scale and then a flat seventh, also known as the dominant seventh, added on top!

For example in the key of G major, the Dominant seventh chord would start on the note D, the fifth note of the scale. (The fifth note of any scale is called the dominant note)

G A B C D

We would then have a major triad starting on D. The notes in a D major triad are - D F# A

We then simply add a flattened seventh on the top of this major triad. In this case it would be a C natural!

As you can see C is the seventh scale degree of D major but normally in D major we would have a C#. Having a C natural is flattened down by a semitone from the original note C sharp.

Dominant 7th chord, starting on D

Minor Seventh Chord

A minor seventh chord is built using a minor triad with a minor seventh added to the top.

Lets take a look at an example in C minor. The tonic triad of C minor is C, Eb, G now we simply add a minor seventh to the top of this chord. The minor seventh from C natural is Bb. (If these intervals are confusing, have a look at our intervals article). So the chord will be as follows:

C, Eb, G, Bb

Minor 7th chord, starting on C

Major Seventh Chord

A major seventh triad consists of a major triad with an additional major seventh added to the top.

For example let's take the G major tonic triad. This has the notes G, B, D

We now simply add a major seventh to the top of this triad. This would be an F sharp as a major seventh above G natural is an F sharp.

G major seventh will have the notes G, B, D, F sharp

Major seventh chord, starting on G

Diminished Seventh Chord

Diminished seventh chords consist of a diminished triad with a diminished seventh added to the top.

Let's write out a diminished chord starting on B.

A diminished chord starting on B includes the notes B, D, F - remember in a diminished chord we must make sure that the interval of a fifth is diminished.

We can now add in a diminished seventh to the top of this chord. A diminished seventh above B natural is A flat.

So B diminished includes the notes B, D, F, Ab.

Diminished seventh chord, starting on B

Half Diminished Chord

Half diminished chords have a diminished triad with an additional minor seventh. Where a diminished chord had both intervals diminished this one is half diminished because only one of the intervals is diminished!

Let's look at an example in C minor

C minor diminished triad has the notes C, Eb, Gb

Now we simply add in the minor seventh to the top. A minor seventh from C natural is Bb

So C minor half diminished chord has the notes C, Eb, Gb, Bb

Half diminished chord

Augmented Seventh Chord

Augmented seventh chords are built using an augmented triad with an added minor seventh.

Let's look at an example in C major

A C major augmented triad will include the notes C, E, G#. Remember for it to be an augmented triad the interval of a fifth must be an augmented fifth.

Now we simply need to add a minor seventh on the top. The minor seventh above this would be a B flat.

A C major augmented seventh will be C, E, G#, Bb

Augmented seventh chord

Extended Chords

Extended chords are chords that extend past the seventh degree of the chord. An extended chord uses notes from the second octave of a scale:

C major labelled past an octave, 8th, 9th, 10th, 11th, 12th, 13th, 14th , 15th

Once we get past the octave, or the 8th note of the scale, we simply continue counting on - 9th, 10th, 11th etc

In an extended chord we continue adding thirds above, remember chords are most commonly tertian meaning stacking thirds.

These will include 9th, 11th and 13th notes above the root.

Below is an example of some common extended chords

dominant 9th, dominant 11th, dominant 13th

Altered Chords

An altered chord is where one of the notes in the diatonic chord is changed or moved up or down by one semitone. When making an altered chord, you need to remember not to change the tonic, third or seventh notes as these will alter the chord too much.

To learn more about altered chords then check out this blog post. 

altered chord, dominant 9th

Suspended Chords

A suspended chord is one that includes a suspended note. This is almost always a triad with it's 3rd substituted for a 2nd or a 4th.

There are many other examples so to learn more about them please checkout this blog post. 

Suspended Chords, suspended second, suspended fourth

Quartal and Quintal Chords

Although most chords are tertian, meaning built on stacking thirds, there are some exceptions to the rule and these are quartal and quintal chords!

A quartal chord is built by stacking fourths - these fourths will usually either be perfect or augmented. Perfect fourths are the most common.

A quintal chord is, you guessed it, built by stacking fifths! 

quartal and quintal chords

Chord Labelling

Once you understand your chords it is then important to understand how to show and label them in your music.

Chords are labelled in a very specific way and it is important to learn this right from the beginning. The most common way to label chords is through the use of Roman numerals.

But what exactly are Roman numerals?

Roman numerals are simply the numerical system that originated from Ancient Rome. Roman numerals are an extremely clear way for us to indicate to the performer what chord we would like them to play. Each chord is built on a different degree/note of the scale or key we are in, this scale degree gives us the number for the chord.

You will need to understand your Roman numerals up to seven. They are as below:

I, II, III, IV, V, VI, VII

Let's look at an F major scale and label each chord with a Roman numeral. Remember the notes of the F major scale are F, G, A, B b, C, D, E.

F major labelled with Roman numerals

As you can see the first chord is labelled with the Roman numeral I and has the notes F, A, C

The second chord is labelled II and has the notes G, B, D

The third chord is labelled III and has the notes A, C, E

etc.

Let's now apply the labelling to another scale. The below scale is in the key of G major, we know that it is G major as there is one sharp in the key signature. Remember the notes in G major are,

G, A, B, C, D, E, F#, G.

Now we can simply place a triad/ chord above each note. By doing this we end up with the seven chords of G major!

We can also do the same thing even if we are in a minor key. In order to recognise that you are in a minor key however, you need to make sure you are looking at the accidentals in the scale. When writing chords in minor keys, we will most commonly use the harmonic minor scale.

The below scale is in E minor. We know this because it has one sharp in the key signature. We also have the raised seventh, D sharp. Now we can simply label all seven chords in this minor scale. The labelling does not change between the major and minor scales, it is just important to be really clear what key you are in before you label.

In order to label your chords it is important to be confident with key signatures and scales. Without this knowledge it is difficult to work out the correct name for each chord.

E minor scale labelled Roman numerals

In order to label your chords it is important to be confident with key signatures and scales. Without this knowledge it is difficult to work out the correct name for each chord.

Upper and lowercase labelling

Another important aspect when labelling your chords is to know the difference between upper and lowercase labelling. A chord is always defined by its root note, this is what gives us the actual number for the chord. But then it is defined by its tonality i.e. is it major, minor, augmented or diminished?

We can show the tonality of our chord using the labelling. If we use a lower case Roman numeral, we have a minor triad and if we use an upper case Roman numeral we have a major triad.

Furthermore, if your triad is diminished i.e. the interval of a 5th is a diminished 5th, then you will add a small circle to the top right of your Roman numeral.

If the interval of a 5th is an augmented 5th this triad then becomes augmented meaning you need to add a small plus sign to the top right of your Roman numeral.

An Augmented triad is not commonly seen in your major scales but diminished triads are. Augmented triads are usually seen in your harmonic minor scales. See below an example in the major key of F major with each chord labelled correctly to show the root and also the tonality.

Notice how Chord I is major, chord ii is minor, chord iii is minor, chord IV is major, chord V is major, chord vi is minor and chord viio is diminished! This pattern is true for all major scales!

Now see below an example in the minor key of E minor with each chord labelled correctly to show the root and also the tonality.

Notice how chord i is minor, chord ii is minor, chord III+ is augmented, chord iv is minor, chord V is major, chord VI is major and chord viio is diminished. This is true for all harmonic minor scales.

When clear with this method of labelling, chords are then defined by the inversion that they are written in. Read on to find out more.

Chord Inversions

There are three main inversions of diatonic chords. These are:

  • Root Position
  • First Inversion
  • Second Inversion

There are more but these are the main three you should be clear on in basic triads.

Root position is the most usual position of a chord. This is where the chord has it's root at the bottom and will be the lowest note. The root is the home note of the chord, so root position will always sound the most stable.

root position chord c major

1st inversion has the third of the chord at the bottom. The third is the second note of the chord. This inversion will sound slightly less stable than the root position chord.

first inversion chord c major

2nd inversion has the fifth of the chord at the bottom. The fifth is the third note of the chord. This inversion will sound very unstable in comparison to the other chord inversions.

second inversion chord c major

How can you label these effectively?

To label the inversions of chords effectively, it is important to apply the following method.

For root position chords, we will place a small letter 'a' next to the chords labelling. Although this will often be omitted in practice.

For first inversion chords, we will place a small letter 'b' next to the chords labelling.

For second inversion chords, we will place a small letter 'c' next to the chords labelling.

Augmented chords are represented with a small + sign in the top right corner

Diminished chords are represented with a small o sign in the top right corner.

chord labelling Roman numerals symbols

Alternative Labelling

Chords can also be represented using letters.

We represent major chords with a capital letter and no other symbols. For example a capital A on it's own tells the performer to play an A major chord. If you would like this to be a major seventh chord then you have to place a capital M next to the A as well as a small seven in the top right corner. If you do not do this it can be confused with a dominant chord, more on this later!

We represent minor chords with a lowercase letter. You may also see a lower case letter with a lower case m next to it, although this is not strictly necessary. The m is useful when you are writing out letters that are similar in their lowercase and uppercase form. If you would like a minor seventh chord then you simply place the small seven in the top right corner as you did with the major seventh chord.

A dominant seventh chord is represented with an uppercase letter with a seven in the top right corner. Remember a dominant seventh is built on the fifth note of the major scale so whatever the capital letter is, you play the fifth note of that major scale with the additional seventh. If for example you have a capital C, the you will not have root c but rather your root will be G, the fifth note of the scale.

An augmented chord is represented using a small plus sign in the top right corner. You may also see a sharp sign to signify the raising of the fifth or even an abbreviated version of the word augmented 'aug'. For example c augmented would be written as follows C+.

A diminished chord is represented using a small circle in the top right corner but you may also see a flat sign to signify the diminished fifth or simply the abbreviated version of the word diminished 'dim'.

A half diminished chord has a very similar symbol to the diminished chord but the small circle now has a slash through it.

If extending the chord, a small number of what the additional third is will be written in the top right corner.

We represent minor chords with a lowercase letter. You may also see a lower case letter with a lower case m next to it, although this is not strictly necessary. The m is useful when you are writing out letters that are similar in their lowercase and uppercase form. If you would like a minor seventh chord then you simply place the small seven in the top right corner as you did with the major seventh chord.

A dominant seventh chord is represented with an uppercase letter with a seven in the top right corner. Remember a dominant seventh is built on the fifth note of the major scale so whatever the capital letter is, you play the fifth note of that major scale with the additional seventh. If for example you have a capital C, the you will not have root c but rather your root will be G, the fifth note of the scale.

An augmented chord is represented using a small plus sign in the top right corner. You may also see a sharp sign to signify the raising of the fifth or even an abbreviated version of the word augmented 'aug'. For example c augmented would be written as follows C+.

A diminished chord is represented using a small circle in the top right corner but you may also see a flat sign to signify the diminished fifth or simply the abbreviated version of the word diminished 'dim'.

A half diminished chord has a very similar symbol to the diminished chord but the small circle now has a slash through it.

If extending the chord, a small number of what the additional third is will be written in the top right corner.

A dominant seventh chord is represented with an uppercase letter with a seven in the top right corner. Remember a dominant seventh is built on the fifth note of the major scale so whatever the capital letter is, you play the fifth note of that major scale with the additional seventh. If for example you have a capital C, the you will not have root c but rather your root will be G, the fifth note of the scale.

An augmented chord is represented using a small plus sign in the top right corner. You may also see a sharp sign to signify the raising of the fifth or even an abbreviated version of the word augmented 'aug'. For example c augmented would be written as follows C+.

A diminished chord is represented using a small circle in the top right corner but you may also see a flat sign to signify the diminished fifth or simply the abbreviated version of the word diminished 'dim'.

A half diminished chord has a very similar symbol to the diminished chord but the small circle now has a slash through it.

If extending the chord, a small number of what the additional third is will be written in the top right corner.

 

An augmented chord is represented using a small plus sign in the top right corner. You may also see a sharp sign to signify the raising of the fifth or even an abbreviated version of the word augmented 'aug'. For example c augmented would be written as follows C+.

A diminished chord is represented using a small circle in the top right corner but you may also see a flat sign to signify the diminished fifth or simply the abbreviated version of the word diminished 'dim'.

A half diminished chord has a very similar symbol to the diminished chord but the small circle now has a slash through it.

If extending the chord, a small number of what the additional third is will be written in the top right corner.

 

A diminished chord is represented using a small circle in the top right corner but you may also see a flat sign to signify the diminished fifth or simply the abbreviated version of the word diminished 'dim'.

A half diminished chord has a very similar symbol to the diminished chord but the small circle now has a slash through it.

If extending the chord, a small number of what the additional third is will be written in the top right corner.

 

A half diminished chord has a very similar symbol to the diminished chord but the small circle now has a slash through it.

If extending the chord, a small number of what the additional third is will be written in the top right corner.

 

If extending the chord, a small number of what the additional third is will be written in the top right corner.

 

alternative chord labels, chord labelling

Figured Bass

Another slightly older way to label chords is by using figured bass. Figured bass originated from the baroque period. Here is a basic description of what it is:

You can find more out about figured bass here. For now we will do a very brief description.

The numbers in a figured bass labelling, literally indicate to us the interval above the root.

We would label a root position chord with the figures 5/3. This will mean a third above the root and a fifth above the root. Take a look at the C major chord below and you can see how this works.

We would then label a first inversion chord with the figures 6/3. This will mean a third above the root and a sixth above the root. Again, take a look at the C major chord below and you can see how this works.

We would then label a second inversion chord with the figures 6/4. This will mean a fourth above the root and a sixth above the root. Take a look at the chord below.

figured bass root position 5/3

We would then label a first inversion chord with the figures 6/3. This will mean a third above the root and a sixth above the root. Again, take a look at the C major chord below and you can see how this works.

We would then label a second inversion chord with the figures 6/4. This will mean a fourth above the root and a sixth above the root. Take a look at the chord below.

figured bass, first inversion explained

We would then label a second inversion chord with the figures 6/4. This will mean a fourth above the root and a sixth above the root. Take a look at the chord below. 

figured bass, second inversion chord explained

How to use chords

Chords are the foundation of all harmony. In a music composition we have to use chord progressions to support the notes in your melody. A chord progression is a sequence of chords in a specific order. These chords support the melody and the rhythm and are absolutely key to writing your own songs and compositions. To learn more about chords progressions make sure to check out this blog post.

chord progression example Adele hello
Author: Jade Bultitude
Jade is an experienced musician and teacher as well as being the founder of Music Theory Foundations.
 

She has been helping people learn music theory for more than 10 years from pre school children all the way to degree level studies.

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