Chord Construction & Formulas

A group of notes (typically 3 or more) that are played together is called a chord

Here we’ll cover the most common types of chords, using the notes from the C Major Scale in our examples.

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A Dyad is a set of 2 notes. Technically, they are not considered chords by strict music theory definition (which is 3 or more different pitches), however they can imply the character of chords from the interval between the notes.

A well-known dyad is a Power Chord, which is simply a Root Note together with another note that’s separated by a Perfect 5th interval.

In the C Major scale, a C5 Power Chord is simply the notes C & G, where C is the root note, and G is a perfect 5th interval away:


You can create a dyad from any two notes. Let’s try one more and take the notes C & E from the C Major Scale.


In this example, C & E are separated by a Major 3rd Interval. This will imply a major tonality and is important for the most fundamental chord type – the Triad.


Triads are the most basic form of a chord. They are comprised of 3-notes – root, 3rd interval, & 5th interval.

For example, we can create a C Major Triad from the notes C, E, and G of the C Major Scale.


Remember from our dyad examples on the previous page, the notes C & E are separated by a Major 3rd interval, and the notes C & G are separated by a Perfect 5th interval. This combination of intervals gives us a Major Triad.

Seventh Chords

A seventh chord consists of a root, 3rd, 5th, & 7th interval. These chords have a bit more ‘colour’ than triads and you will often hear them in Blues and Jazz.

Using the C Major Scale once again, we would take the notes C, E, G, and B. This gives us a C Major Seventh chord because of the Major 3rd, Perfect 5th, and Major 7th intervals.


As with triads, there are also several types of Seventh Chords. Here are the most common:

Added Tone Chords

Added tone chords are triads with ‘added’ notes other than the 7th interval.

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9th Chords

These chords ‘extend’ beyond a seventh chord by adding a 9th interval. You can also think of a 9th as a major 2nd interval up an octave from the root note.

The 5th interval is often omitted from the chord because it does not affect its tonality. This also makes it easier for musicians to play these chords on their instrument.

11th & 13th Chords

These chords once again extend seventh chords by adding an 11th interval or a 13th interval. You can also think of an 11th as being a perfect 4th interval up an octave from the root note, and a 13th a major 6th interval up an octave.

With Major 11 & Dominant 11 chords, the Major 3rd interval is typically omitted because it creates an unpleasant dissonance. You’ll often see the 5th interval omitted because it does not affect the tonality of the chord.

For any 13th chord, typically omit the 5th, 9th, and 11th intervals. This is for practical purposes as they don’t impact the ’13th’ character of the chord and are easier for musicians to play as a result.

Chord Inversions

You don’t have to always play chords in their scalar order. By rearranging the notes you can create what are
called chord inversions.

An inversion moves the root note to other places in the chord other than the bass note.

The intervals and notes remain the same, but where you might play a C Major chord as C-E-G (in root position) you can also form a C Major chord with an E in the bass as E-G-C (first inversion). The chord is the same but it will sound slightly different.

The root position chord is a fairly normal and stable sound, while the first and second (and sometimes third inversion with seventh chords) give it a different feel or sense of instability.

Often, inversions are used to smooth out a chord progression so that there aren’t awkward jumps between the notes of successive chords.

Example: Moving from C Major (C E G) to A Minor (A C E)

Let’s start with the chords arranged in their root position, with the root note placed at the bottom:

When both chords are in root position, every note between chords is separated by a wide Major 6th interval. It will still sound good since both chords are still in key, but it might sound a bit jarring.

If we invert the A Minor chord so that the C note was in the root instead, we only have 1 note changing between chords. Only the G moves to an A by 1 whole step. This will sound really smooth and subtle!

Triad Inversions

Triads have 2 inversions in addition to its root position. We’ll use a Major Triad (1 – 3 – 5) as an example in the table below, but this works for any triad – Minor, Diminished, Augmented, or Suspended.

In the First Inversion, the 3rd interval becomes the bass note instead of the root note. In the Second Inversion, the 5th interval of the chord becomes the bass note instead of the root note.

This is reflected in the chord name, such as Cmaj/E which means ‘a C major chord with E as the bass note.’

A quick way to create inversions is to raise or lower any of the notes in the triad by an octave. This will change the bass note and create an inversion.

Seventh Chord Inversions

Since Seventh Chords have 4 notes, they have an additional inversion. Let’s use a Major 7th chord as an example, but this works with any seventh chord.

Once again, with each inversion the bass note is no longer the root note of the chord.

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Chord Voicing

When rearranging the order of notes in a chord but the bass note stays the same, you create chord voicings.

Open Voicings spread the notes across more than one octave. For example, this root-position C Major chord is voiced with the E note an octave higher than the C & G.

Open Chord Voicing

Close Voicings arrange the notes tightly. Notice we have moved the E note into the same octave as C & G.

Close Chord Voicing

As long as the bass note stays the same (changing the bass note creates chord inversions), you can arrange the other notes in the chord however you want to create different voicings. They can be used in several ways:

  • Tonal qualities: Close voicings can sound ‘dense’ while open voicings can sound ‘airy.’
  • Composition: For smoother transitions between chords.
  • Comfort: Certain instruments have more comfortable voicings for finger placement & stretches.
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